Origin and timing of New Zealand's earliest domestic chickens: Polynesian commensals or European introductions?

NASA Astrophysics Data System (ADS)

Wood, Jamie R.; Herrera, Michael J. B.; Scofield, R. Paul; Wilmshurst, Janet M.

2016-08-01

Human settlers transported chickens (Gallus gallus domesticus) to most East Polynesian archipelagos between AD 1000 and 1300; however, it has long been assumed that New Zealand was an exception. Despite the fact that chicken bones have been recovered from localities of early archaeological middens in New Zealand, their age and genetic relationships have never been critically assessed. Here, we test the assumption that chickens were not introduced to New Zealand during prehistory through ancient DNA and radiocarbon analyses of chicken bones from sites of Māori middens containing prehistoric material. The chickens belong to the widespread mitochondrial control region haplogroup E. Radiocarbon dating reveals that the bones are not prehistoric, but are still the earliest chicken remains known from New Zealand. Two of the bones pre-date permanent European settlement (ca 1803s onwards) but overlap with the arrival of James Cook's second voyage (1773-1774), and, therefore, they are likely to be chickens, or progeny thereof, liberated during that voyage. Our results support the idea that chickens were first introduced to New Zealand by Europeans, and provide new insights into Māori uptake and integration of resources introduced during the early post-European period.

78 FR 12084 - Public Land Order No. 7809; Withdrawal of National Forest System Land for the Settler's Grove of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-21

... Relay Service (FIRS) at 1-800-877-8339 to contact either of the above individuals. The FIRS is available... to the United States Forest Service for protection of the Settler's Grove of Ancient Cedars Botanical... under the mineral leasing laws, for the protection of the Settler's Grove of Ancient Cedars Botanical...

Pioneering Mars: Turning the Red Planet Green with Earth's Smallest Settlers

ERIC Educational Resources Information Center

Cwikla, Julie; Milroy, Scott; Reider, David; Skelton, Tara

2014-01-01

Pioneering Mars: Turning the Red Planet Green with the Earth's Smallest Settlers (http://pioneeringmars.org) provides a partnership model for STEM (science, technology, engineering, and mathematics) learning that brings university scientists together with high school students to investigate whether cyanobacteria from Antarctica could survive on…

On the Frontier of School Reform with Trailblazers, Pioneers, and Settlers.

ERIC Educational Resources Information Center

Schlechty, Phillip C.

1993-01-01

Educators leading restructuring efforts must recognize five roles people play in the change process (trailblazers, pioneers, settlers, stay-at-homes, and saboteurs) and provide training, encouragement, and support differentially for each role. The article examines four questions that must be answered to move the restructuring process forward…

Compact Cell Settlers for Perfusion Cultures of Microbial (and Mammalian) Cells.

PubMed

Freeman, Cassandra A; Samuel, Premsingh S D; Kompala, Dhinakar S

2017-07-01

As microbial secretory expression systems have become well developed for microbial yeast cells, such as Saccharomyces cerevisiae and Pichia pastoris, it is advantageous to develop high cell density continuous perfusion cultures of microbial yeast cells to retain the live and productive yeast cells inside the perfusion bioreactor while removing the dead cells and cell debris along with the secreted product protein in the harvest stream. While the previously demonstrated inclined or lamellar settlers can be used for such perfusion bioreactors for microbial cells, the size and footprint requirements of such inefficiently scaled up devices can be quite large in comparison to the bioreactor size. Faced with this constraint, we have now developed novel, patent-pending compact cell settlers that can be used more efficiently with microbial perfusion bioreactors to achieve high cell densities and bioreactor productivities. Reproducible results from numerous month-long perfusion culture experiments using these devices attached to the 5 L perfusion bioreactor demonstrate very high cell densities due to substantial sedimentation of the larger live yeast cells which are returned to the bioreactor, while the harvest stream from the top of these cell settlers is a significantly clarified liquid, containing less than 30% and more typically less than 10% of the bioreactor cell concentration. Size of cells in the harvest is smaller than that of the cells in the bioreactor. Accumulated protein collected from the harvest and rate of protein accumulation is significantly (> 6x) higher than the protein produced in repeated fed-batch cultures over the same culture duration. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:913-922, 2017. © 2017 American Institute of Chemical Engineers.

SLUDGE RETRIEVAL FROM HANFORD K WEST BASIN SETTLER TANKS

DOE Office of Scientific and Technical Information (OSTI.GOV)

ERPENBECK EG; LESHIKAR GA

In 2010, an innovative, remotely operated retrieval system was deployed to successfully retrieve over 99.7% of the radioactive sludge from ten submerged tanks in Hanford's K-West Basin. As part of K-West Basin cleanup, the accumulated sludge needed to be removed from the 0.5 meter diameter by 5 meter long settler tanks and transferred approximately 45 meters to an underwater container for sampling and waste treatment. The abrasive, dense, non-homogeneous sludge was the product of the washing process of corroded nuclear fuel. It consists of small (less than 600 micron) particles of uranium metal, uranium oxide, and various other constituents, potentiallymore » agglomerated or cohesive after 10 years of storage. The Settler Tank Retrieval System (STRS) was developed to access, mobilize and pump out the sludge from each tank using a standardized process of retrieval head insertion, periodic high pressure water spray, retraction, and continuous pumping of the sludge. Blind operations were guided by monitoring flow rate, radiation levels in the sludge stream, and solids concentration. The technology developed and employed in the STRS can potentially be adapted to similar problematic waste tanks or pipes that must be remotely accessed to achieve mobilization and retrieval of the sludge within.« less

SLUDGE PARTICLE SEPAPATION EFFICIENCIES DURING SETTLER TANK RETRIEVAL INTO SCS-CON-230

DOE Office of Scientific and Technical Information (OSTI.GOV)

DEARING JI; EPSTEIN M; PLYS MG

2009-07-16

The purpose of this document is to release, into the Hanford Document Control System, FA1/0991, Sludge Particle Separation Efficiencies for the Rectangular SCS-CON-230 Container, by M. Epstein and M. G. Plys, Fauske & Associates, LLC, June 2009. The Sludge Treatment Project (STP) will retrieve sludge from the 105-K West Integrated Water Treatment System (IWTS) Settler Tanks and transfer it to container SCS-CON-230 using the Settler Tank Retrieval System (STRS). The sludge will enter the container through two distributors. The container will have a filtration system that is designed to minimize the overflow of sludge fines from the container to themore » basin. FAI/09-91 was performed to quantify the effect of the STRS on sludge distribution inside of and overflow out of SCS-CON-230. Selected results of the analysis and a system description are discussed. The principal result of the analysis is that the STRS filtration system reduces the overflow of sludge from SCS-CON-230 to the basin by roughly a factor of 10. Some turbidity can be expected in the center bay where the container is located. The exact amount of overflow and subsequent turbidity is dependent on the density of the sludge (which will vary with location in the Settler Tanks) and the thermal gradient between the SCS-CON-230 and the basin. Attachment A presents the full analytical results. These results are applicable specifically to SCS-CON-230 and the STRS filtration system's expected operating duty cycles.« less

Effect of geometric and process variables on the performance of inclined plate settlers in treating aquacultural waste.

PubMed

Sarkar, Sudipto; Kamilya, Dibyendu; Mal, B C

2007-03-01

Inclined plate settlers are used in treating wastewater due to their low space requirement and high removal rates. The prediction of sedimentation efficiency of these settlers is essential for their performance evaluation. In the present study, the technique of dimensional analysis was applied to predict the sedimentation efficiency of these inclined plate settlers. The effect of various geometric parameters namely, distance between plates (w(p)), plate angle (alpha), length of plate (l(p)), plate roughness (epsilon(p)), number of plates (n(p)) and particle diameter (d(s)) on the dynamic conditions, influencing the sedimentation process was studied. From the study it was established that neither the Reynolds criterion nor the Froude criterion was singularly valid to simulate the sedimentation efficiency (E) for different values of w(p) and flow velocity (v(f)). Considering the prevalent scale effect, simulation equations were developed to predict E at different dynamic conditions. The optimum dynamic condition producing the maximum E is also discussed.

Digital Narratives as a Means of Shifting Settler-Teacher Horizons toward Reconciliation

ERIC Educational Resources Information Center

Bissell, Alexandra; Korteweg, Lisa

2016-01-01

The Truth and Reconciliation Commission's "Calls to Action" report (2015), in the section "Education for Reconciliation" (p. 7, #62-63), calls for the integration of Indigenous knowledge and teaching methods into the curriculum and for better preparation of teachers to deliver Indigenous content. Settler-teachers, however, have…

Racist Ordering, Settler Colonialism, and EdTPA: A Participatory Policy Analysis

ERIC Educational Resources Information Center

Tuck, Eve; Gorlewski, Julie

2016-01-01

This article tells the story of an intervention by a collective of teacher educators on New York State's adoption of edTPA. Too often in education policy analysis, issues of race are discussed briefly, if at all. This article argues that attending to constructions of race specific to settler colonialism is an important approach to education policy…

The effect of adult aggression on habitat selection by settlers of two coral-dwelling damselfishes.

PubMed

Ben-Tzvi, Ofer; Kiflawi, Moshe; Polak, Omer; Abelson, Avigdor

2009-01-01

Coral-reef fishes experience a major challenge when facing settlement in a multi-threat environment, within which, using settlement cues, they need to select a suitable site. Studies in laboratories and artificial setups have shown that the presence of conspecific adults often serves as a positive settlement cue, whose value is explained by the increased survival of juveniles in an already proven fit environment. However, settlement in already inhabited corals may expose the recruits to adult aggression. Daily observations and manipulation experiments were used in the present study, which was conducted in the natural reef. We revealed differential strategies of settlers, which do not necessarily join conspecific adults. Dascyllus aruanus prefer to settle near (not with) their aggressive adults, and to join them only after gaining in size; whereas Dascyllus marginatus settlers in densely populated reefs settle independently of their adult distribution. Our results present different solutions to the challenges faced by fish recruits while selecting their microhabitat, and emphasize the complexity of habitat selection by the naïve settlers. Although laboratory experiments are important to the understanding of fish habitat selection, further studies in natural habitats are essential in order to elucidate the actual patterns of settlement and habitat selection, which are crucial for the survival of coral-reef fish populations.

The effect of Piper betle and Psidium guajava extracts on the cell-surface hydrophobicity of selected early settlers of dental plaque.

PubMed

Razak, Fathilah Abdul; Othman, Rofina Yasmin; Rahim, Zubaidah Haji Abd

2006-06-01

The adhesion of early settlers of dental plaque to the tooth surface has a role in the initiation of the development of dental plaque. The hydrophobic surface properties of the bacteria cell wall are indirectly responsible for the adhesion of the bacteria cell to the acquired pellicle on the tooth surfaces. In this study, the effect of aqueous extract of two plants (Psidium guajava and Piper betle) on the cell-surface hydro-phobicity of early settlers of dental plaque was determined in vitro. Hexadecane, a hydrocarbon was used to represent the hydrophobic surface of the teeth in the oral cavity. It was found that treatment of the early plaque settlers with 1 mg/ml extract of Psidium guajava reduced the cell-surface hydrophobicity of Strep. sanguinis, Strep. mitis and Actinomyces sp. by 54.1%, 49.9% and 40.6%, respectively. Treatment of these bacteria with the same concentration of Piper betle however, showed a comparatively lesser effect (< 10%). It was also observed that the anti-adhesive effect of the two extracts on the binding of the early plaque settlers to hexadecane is concentration dependent.

Reconsidering the Summer Residence: The City-Text, Historical Commemoration and Banal Settler Geography

ERIC Educational Resources Information Center

Smith, Bryan

2017-01-01

Author Bryan Smith agrees that critiques of Sir John A. Macdonald, and Cornwallis as unworthy of public commemoration are warranted and necessary, particularly as each was instrumental in cementing settler-colonial projects of dominion and erasure of Indigenous populations. However, he observes that each figure is but one point (or multiple) in…

Origin and earliest state of the earth's hydrosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cogley, J.G.; Henderson-Sellers, A.

1984-05-01

The origin and earliest history of the earth's hydrosphere, the inventory of excess volatiles defined by Rubey in 1951, can be constrained within wide but useful limits by a consideration of empirical and theoretical evidence from astrophysics and geology. Models for the evolution of the solar system from the protoplanetary nebula and for the growth of the earth to its present dimensions suggest quite strongly that the hydrosphere came into being during accretion. Its format, with H/sub 2/O mostly in the oceans, CO/sub 2/ mostly in sediments, and a residual atmosphere dominated by N/sub 2/, CO/sub 2/, and H/sub 2/Omore » was established at a very early data and has persisted without large, destabilizing climatic excursions until the present day. Alternative accounts of early history, in which the earth either loses a massive primordial atmosphere or acquires its secondary atmosphere by gradual degassing, seem improbable on the basis of a series of circumstantial but cumulatively persuasive arguments. The difficulty of dissipating a massive atmosphere of solar composition in reasonable times, the likelihood that accretion was a highly energetic process and that it triggered early segregation of the core, and the tendency of the planet to accumulate volatiles preferentially in the later stages of accretion are examples of arguments favoring an early origin for the hydrosphere. Several geological isotope systems which can be sampled today require early separation of the atmosphere and probably the hydrosphere ass a whole; these systems recorrd radiogenic enrichment patterns in the noble gases and stable isotope fractionations which suggest an early origin of the biosphere. Certain geological indicators of atmsopheric composition. and the broadly equable character of the rock record, are also consistent with a hydrosphere established in the earliest stages of history and having an initial neutral or weakly reduced composition.« less

[New settlers comb jellies Mnemiopsis leidyi (A. Agassiz) and Beroe ovata Mayer 1912 and their influence on the pelagic ecosystem of the northeastern part of the Black Sea].

PubMed

Shiganova, T A; Musaeva, E I; Bulgakova, Iu V; Mirzoian, Z A; MartynIuk, M L

2003-01-01

We analyzed the condition of pelagic ecosystem of northeastern Black Sea influenced by expansion of a new settler Beroe ovata in 1999-2001. Expansion of B. ovata considerably decreased the population of another new settler Mnemiopsis leidyi that deformed the Black Sea ecosystem for over a decade. Reduction of M. leidyi population limited its influence on the ecosystem and, consequently, we observed reestablishment of the main components of the Black Sea pelagic ecosystem--zooplankton and fish, their spawn and larvae. The relationship between annual and seasonal variability of the population and biomass of the both new settlers M. leidyi and B. ovata are discussed.

29 CFR 4022.10 - Earliest PBGC Retirement Date.

Code of Federal Regulations, 2010 CFR

2010-07-01

... after the date the participant reaches age 55, the Earliest PBGC Retirement Date for the participant is... reaches age 55, the Earliest PBGC Retirement Date for the participant is the date the participant reaches... participant reaches age 55, the PBGC will make a determination, under the facts and circumstances, as to...

29 CFR 4022.10 - Earliest PBGC Retirement Date.

Code of Federal Regulations, 2011 CFR

2011-07-01

... after the date the participant reaches age 55, the Earliest PBGC Retirement Date for the participant is... reaches age 55, the Earliest PBGC Retirement Date for the participant is the date the participant reaches... participant reaches age 55, the PBGC will make a determination, under the facts and circumstances, as to...

The peopling of South America and the trans-Andean gene flow of the first settlers.

PubMed

Gómez-Carballa, Alberto; Pardo-Seco, Jacobo; Brandini, Stefania; Achilli, Alessandro; Perego, Ugo A; Coble, Michael D; Diegoli, Toni M; Álvarez-Iglesias, Vanesa; Martinón-Torres, Federico; Olivieri, Anna; Torroni, Antonio; Salas, Antonio

2018-06-01

Genetic and archaeological data indicate that the initial Paleoindian settlers of South America followed two entry routes separated by the Andes and the Amazon rainforest. The interactions between these paths and their impact on the peopling of South America remain unclear. Analysis of genetic variation in the Peruvian Andes and regions located south of the Amazon River might provide clues on this issue. We analyzed mitochondrial DNA variation at different Andean locations and >360,000 autosomal SNPs from 28 Native American ethnic groups to evaluate different trans-Andean demographic scenarios. Our data reveal that the Peruvian Altiplano was an important enclave for early Paleoindian expansions and point to a genetic continuity in the Andes until recent times, which was only marginally affected by gene flow from the Amazonian lowlands. Genomic variation shows a good fit with the archaeological evidence, indicating that the genetic interactions between the descendants of the settlers that followed the Pacific and Atlantic routes were extremely limited. © 2018 Gómez-Carballa et al.; Published by Cold Spring Harbor Laboratory Press.

Coral reef fish populations can persist without immigration

PubMed Central

Salles, Océane C.; Maynard, Jeffrey A.; Joannides, Marc; Barbu, Corentin M.; Saenz-Agudelo, Pablo; Almany, Glenn R.; Berumen, Michael L.; Thorrold, Simon R.; Jones, Geoffrey P.; Planes, Serge

2015-01-01

Determining the conditions under which populations may persist requires accurate estimates of demographic parameters, including immigration, local reproductive success, and mortality rates. In marine populations, empirical estimates of these parameters are rare, due at least in part to the pelagic dispersal stage common to most marine organisms. Here, we evaluate population persistence and turnover for a population of orange clownfish, Amphiprion percula, at Kimbe Island in Papua New Guinea. All fish in the population were sampled and genotyped on five occasions at 2-year intervals spanning eight years. The genetic data enabled estimates of reproductive success retained in the same population (reproductive success to self-recruitment), reproductive success exported to other subpopulations (reproductive success to local connectivity), and immigration and mortality rates of sub-adults and adults. Approximately 50% of the recruits were assigned to parents from the Kimbe Island population and this was stable through the sampling period. Stability in the proportion of local and immigrant settlers is likely due to: low annual mortality rates and stable egg production rates, and the short larval stages and sensory capacities of reef fish larvae. Biannual mortality rates ranged from 0.09 to 0.55 and varied significantly spatially. We used these data to parametrize a model that estimated the probability of the Kimbe Island population persisting in the absence of immigration. The Kimbe Island population was found to persist without significant immigration. Model results suggest the island population persists because the largest of the subpopulations are maintained due to having low mortality and high self-recruitment rates. Our results enable managers to appropriately target and scale actions to maximize persistence likelihood as disturbance frequencies increase. PMID:26582017

Coral reef fish populations can persist without immigration.

PubMed

Salles, Océane C; Maynard, Jeffrey A; Joannides, Marc; Barbu, Corentin M; Saenz-Agudelo, Pablo; Almany, Glenn R; Berumen, Michael L; Thorrold, Simon R; Jones, Geoffrey P; Planes, Serge

2015-11-22

Determining the conditions under which populations may persist requires accurate estimates of demographic parameters, including immigration, local reproductive success, and mortality rates. In marine populations, empirical estimates of these parameters are rare, due at least in part to the pelagic dispersal stage common to most marine organisms. Here, we evaluate population persistence and turnover for a population of orange clownfish, Amphiprion percula, at Kimbe Island in Papua New Guinea. All fish in the population were sampled and genotyped on five occasions at 2-year intervals spanning eight years. The genetic data enabled estimates of reproductive success retained in the same population (reproductive success to self-recruitment), reproductive success exported to other subpopulations (reproductive success to local connectivity), and immigration and mortality rates of sub-adults and adults. Approximately 50% of the recruits were assigned to parents from the Kimbe Island population and this was stable through the sampling period. Stability in the proportion of local and immigrant settlers is likely due to: low annual mortality rates and stable egg production rates, and the short larval stages and sensory capacities of reef fish larvae. Biannual mortality rates ranged from 0.09 to 0.55 and varied significantly spatially. We used these data to parametrize a model that estimated the probability of the Kimbe Island population persisting in the absence of immigration. The Kimbe Island population was found to persist without significant immigration. Model results suggest the island population persists because the largest of the subpopulations are maintained due to having low mortality and high self-recruitment rates. Our results enable managers to appropriately target and scale actions to maximize persistence likelihood as disturbance frequencies increase. © 2015 The Author(s).

The earliest settlers of Mesoamerica date back to the late Pleistocene.

PubMed

Stinnesbeck, Wolfgang; Becker, Julia; Hering, Fabio; Frey, Eberhard; González, Arturo González; Fohlmeister, Jens; Stinnesbeck, Sarah; Frank, Norbert; Terrazas Mata, Alejandro; Benavente, Martha Elena; Avilés Olguín, Jerónimo; Aceves Núñez, Eugenio; Zell, Patrick; Deininger, Michael

2017-01-01

Preceramic human skeletal remains preserved in submerged caves near Tulum in the Mexican state of Quintana Roo, Mexico, reveal conflicting results regarding 14C dating. Here we use U-series techniques for dating a stalagmite overgrowing the pelvis of a human skeleton discovered in the submerged Chan Hol cave. The oldest closed system U/Th age comes from around 21 mm above the pelvis defining the terminus ante quem for the pelvis to 11311±370 y BP. However, the skeleton might be considerable older, probably as old as 13 ky BP as indicated by the speleothem stable isotope data. The Chan Hol individual confirms a late Pleistocene settling of Mesoamerica and represents one of the oldest human osteological remains in America.

The earliest settlers of Mesoamerica date back to the late Pleistocene

PubMed Central

Becker, Julia; Hering, Fabio; Frey, Eberhard; González, Arturo González; Fohlmeister, Jens; Stinnesbeck, Sarah; Frank, Norbert; Terrazas Mata, Alejandro; Benavente, Martha Elena; Avilés Olguín, Jerónimo; Aceves Núñez, Eugenio; Zell, Patrick; Deininger, Michael

2017-01-01

Preceramic human skeletal remains preserved in submerged caves near Tulum in the Mexican state of Quintana Roo, Mexico, reveal conflicting results regarding 14C dating. Here we use U-series techniques for dating a stalagmite overgrowing the pelvis of a human skeleton discovered in the submerged Chan Hol cave. The oldest closed system U/Th age comes from around 21 mm above the pelvis defining the terminus ante quem for the pelvis to 11311±370 y BP. However, the skeleton might be considerable older, probably as old as 13 ky BP as indicated by the speleothem stable isotope data. The Chan Hol individual confirms a late Pleistocene settling of Mesoamerica and represents one of the oldest human osteological remains in America. PMID:28854194

Earliest English Definitions of Anaisthesia and Anaesthesia.

PubMed

Haridas, Rajesh P

2017-11-01

The earliest identified English definition of the word anaisthesia was discovered in the first edition (1684) of A Physical Dictionary, an English translation of Steven Blankaart's medical dictionary, Lexicon Medicum Graeco-Latinum. This definition was almost certainly the source of the definition of anaesthesia which appeared in Dictionarium Anglo-Britannicum (1708), a general-purpose English dictionary compiled by the lexicographer John Kersey. The words anaisthesia and anaesthesia have not been identified in English medical or surgical publications that antedate the earliest English dictionaries in which they are known to have been defined.

Manipulating the reported age in earliest memories.

PubMed

Wessel, Ineke; Schweig, Theresa; Huntjens, Rafaële J C

2017-11-02

Previous work suggests that the estimated age in adults' earliest autobiographical memories depends on age information implied by the experimental context [e.g., Kingo, O. S., Bohn, A., & Krøjgaard, P. (2013). Warm-up questions on early childhood memories affect the reported age of earliest memories in late adolescence. Memory, 21(2), 280-284. doi: 10.1080/09658211.2012.729598 ] and that the age in decontextualised snippets of memory is younger than in more complete accounts (i.e., event memories [Bruce, D., Wilcox-O'Hearn, L. A., Robinson, J. A., Phillips-Grant, K., Francis, L., & Smith, M. C. (2005). Fragment memories mark the end of childhood amnesia. Memory & Cognition, 33(4), 567-576. doi: 10.3758/BF03195324 ]). We examined the malleability of the estimated age in undergraduates' earliest memories and its relation with memory quality. In Study 1 (n = 141), vignettes referring to events happening at age 2 rendered earlier reported ages than examples referring to age 6. Exploratory analyses suggested that event memories were more sensitive to the age manipulation than memories representing a single, isolated scene (i.e., snapshots). In Study 2 (n = 162), asking self-relevant and public-event knowledge questions about participants' preschool years prior to retrieval yielded comparable average estimated ages. Both types of semantic knowledge questions rendered earlier memories than a no-age control task. Overall, the reported age in snapshots was younger than in event memories. However, age-differences between memory types across conditions were not statistically significant. Together, the results add to the growing literature indicating that the average age in earliest memories is not as fixed as previously thought.

Reflexive Positioning in a Politically Sensitive Situation: Dealing with the Threats of Researching the West Bank Settler Experience

ERIC Educational Resources Information Center

Possick, Chaya

2009-01-01

For the past 7 years, the author has conducted qualitative research projects revolving around the experiences of West Bank settlers. The political situation in Israel in general, and the West Bank in particular, has undergone rapid and dramatic political, military, and social changes during this period. In highly politically sensitive situations…

The Mexican Outsiders: A Community History of Marginalization and Discrimination in California.

ERIC Educational Resources Information Center

Menchaca, Martha

Based on oral histories and archival documents, this book reconstructs the unwritten history of the Mexican-origin community of Santa Paula, California. This previously unwritten history contrasts sharply with the official version, which focuses on Anglo American accomplishments and excludes the area's earliest settlers and longest…

Age at earliest reported memory: associations with personality traits, behavioral health, and repression.

PubMed

Spirrison, C L; McCarley, N G

2001-09-01

The present study examined relationships between the age at earliest memory and the personality traits and behavioral health of 107 undergraduates. Participants answered questions on their earliest memory and completed the Myers-Briggs Type Indicator (MBTI) and a medical history form. Analyses indicated that continuous scores on two MBTI scales (Sensing-Intuition and Judging-Perceiving) were inversely related to age at earliest memory as were participant's self-reported drug and alcohol problems, emotional and psychological symptoms, accident rates, physical symptoms, and satisfaction with health. Respondents who reported first memories at or after 7 years of age (i.e., approximately 1 SD above the mean age at recalled memory) were classified as repressors. Repressors scored in the Sensing and Judging directions on the MBTI and reported significantly fewer emotional symptoms, accidents, psychological symptoms, and less health satisfaction than nonrepressors. Results are consistent with the age at earliest memory and repression literature and support the use of earliest memory age as an index of repression.

Alaska Native Land Claims. [Textbook].

ERIC Educational Resources Information Center

Arnold, Robert D.; And Others

Written for students at the secondary level, this textbook on Alaska Native land claims includes nine chapters, eight appendices, photographs, maps, graphs, bibliography, and an index. Chapters are titled as follows: (1) Earliest Times (Alaska's first settlers, eighteenth century territories, and other claimants); (2) American Indians and Their…

Earliest Recollections of Childhood: A Demographic Analysis.

ERIC Educational Resources Information Center

Mullen, Mary K.

1994-01-01

Four questionnaires examined the association of demographic factors with recollection for 768 adults. Found that the age of earliest memory increased across birth order, was slightly earlier for females than for males, and was earlier for Caucasians than for Asians. (Author/BC)

Andean settlers rush for Amazonia.

PubMed

Serra-vega, J

1990-01-01

Governments of Andean countries (Peru, Bolivia, Colombia, Ecuador, and Venezuela) have encouraged migration to the Amazon Basin, which has contributed to its destruction. Population pressure, landlessness, and poverty are the inducements to migrate. Efforts to populate the Amazon forest were begun as early as 1964 in Peru without international notice. By 1980, logging was allowed in Peru, and Brazil considered colonization of the Amazon essential to national sovereignty. By 1986, outside of Lima, Peru, a development project originally funded by the World Bank, the InterAmerican Development Bank, and the US, resulted in conflicts between settlers and Indians, in loggers indiscriminately cutting, and in farmers using slash and burn techniques to clear forests. Elsewhere the Peruvian Amazon, in San Ignacio, the population was growing by 5.5%/year. The jungle road that had been started but never completed, Carretera Marginal, destroyed 5 million hectares of primary forest, and much of the 600,000 hectares of arable land gained by the road suffered from inappropriate farming practices which caused massive erosion and laterization of the soils. Food crop production declined, and production of coca for cocaine increased. Coca crops are controlled by the Shining Path guerrillas, who are trying to overthrow the Peruvian government. Devastation of Ecuador around Lago Agrio continues. In Colombia, east of Bogota, forests have disappeared and hills have eroded and silted up rivers and dams. The Andean piedmont in Bolivia has also been devastated by loggers and by slash and burn farming. Southeastern Bolivian forests have been cleared for soya bean cultivation on poor soils. Social and economic crises propel people into the remaining forests. The solution is to ease foreign debt, transfer appropriate technology at affordable prices, refuse to finance destructive development, and help to educate and train scientific researchers. Family planning services are also urgently needed

Your Earliest Memory May Be Earlier than You Think: Prospective Studies of Children's Dating of Earliest Childhood Memories

ERIC Educational Resources Information Center

Wang, Qi; Peterson, Carole

2014-01-01

Theories of childhood amnesia and autobiographical memory development have been based on the assumption that the age estimates of earliest childhood memories are generally accurate, with an average age of 3.5 years among adults. It is also commonly believed that early memories will by default become inaccessible later on and this eventually…

French-Canadians, Acadians and the French in New England. A Learning Activity Packet.

ERIC Educational Resources Information Center

Maine Univ., Orono. New England - Atlantic Provinces - Quebec Center.

The history of the French-Canadians from their beginnings to the present time is the topic of this Learning Activity Packet (LAP). Designed to acquaint students with the French, Canada's earliest permanent settlers following the Indians, the unit is divided into six objectives which include learning activities for each. Students are expected to…

Diet and the evolution of the earliest human ancestors

PubMed Central

Teaford, Mark F.; Ungar, Peter S.

2000-01-01

Over the past decade, discussions of the evolution of the earliest human ancestors have focused on the locomotion of the australopithecines. Recent discoveries in a broad range of disciplines have raised important questions about the influence of ecological factors in early human evolution. Here we trace the cranial and dental traits of the early australopithecines through time, to show that between 4.4 million and 2.3 million years ago, the dietary capabilities of the earliest hominids changed dramatically, leaving them well suited for life in a variety of habitats and able to cope with significant changes in resource availability associated with long-term and short-term climatic fluctuations. PMID:11095758

Earliest Marker for Autism Found in Young Infants

MedlinePlus

... Release Wednesday, November 6, 2013 Earliest marker for autism found in young infants NIH-funded study finds ... to 6-month-old infants later diagnosed with autism. Decline in eye fixation reveals signs of autism ...

Prevalence of TMD symptoms in Turkish migrants and re-settlers from the former Soviet Union in comparison to a German group.

PubMed

Diercke, Katja; Zimmermann, Heiko; Hellmann, Daniel; Kim, Ti-Sun; Fricke, Julia; El Sayed, Nihad; Hagenfeld, Daniel; Kühnisch, Jan; Schmitter, Marc; Becher, Heiko

2016-09-01

The objective of this study was to investigate the prevalence of temporomandibular disorder (TMD) symptoms among Turks and re-settlers with German origin from Russia and to compare those findings with a German group from the same area. Sixty-nine Turkish migrants, 50 re-settlers, and 96 Germans were clinically examined according to a short version of the Research Diagnostic Criteria (RDC/TMD) protocol. The subjects participated in a feasibility study of the German National Cohort and were recruited from the study center Heidelberg/Mannheim of the cluster Baden-Württemberg/Saarland. Significant differences emerged between the three ethnic groups for unassisted opening without pain, maximum unassisted opening, and overbite, with highest values for the German group. No significant differences were found for muscle pain on palpation or muscle and joint pain during opening. As the authors identified significant differences between the different ethnic groups for metric measurements, it might be beneficial to include questions concerning the ethnicity to the German version of the RDC/TMD for further research, to make the results more comparable.

Intrafamilial similarities and cross-generational differences in the earliest childhood memories of daughters, mothers, and grandmothers.

PubMed

Sahin-Acar, Basak; Bakir, Tugce; Kus, Elif Gizem

2017-09-01

This study aimed to examine how daughters, mothers, and grandmothers from the same families resembled each other and how these three generations differed from each other in narrating their earliest childhood memories. Fifty-nine triads from the same families filled out a memory questionnaire and were asked to narrate their earliest childhood memories. Results revealed both intrafamilial similarities and cross-generational difference on characteristics of triads' earliest childhood memories. After earliest childhood memories were coded for memory characteristics, we measured intrafamilial similarities using intra-class correlation coefficients across three generations for each memory characteristic. Results revealed that the earliest childhood memories of members of the same family were significantly similar in terms of level of detail and volume. Although similar patterns among members of the same families were observed in self-related and other-related words, the other/self ratio did not display an intrafamilial similarity. We also measured cross-generational differences and found that daughters' reported age of their earliest childhood memories was dated significantly earlier compared to their grandmothers. Results revealed predominant intrafamilial similarities among the members of the same family and cross-generational differences in terms of the age of the earliest childhood memory.

Earliest Recollections and Birth Order: Two Adlerian Exercises.

ERIC Educational Resources Information Center

Parrott, Les

1992-01-01

Presents two exercises designed to demonstrate the influence of two Adlerian principles on personality. Includes exercises dealing with birth order and earliest recollection. Concludes that the exercises actively demonstrate major concepts for counseling courses in Adlerian psychotherapy. Reports that students rated both exercises highly, with…

Families discovering asthma in their high-risk infants and toddlers with severe persistent disease.

PubMed

Koenig, Karel

2006-02-01

Interpretive phenomenology was used to discover the earliest experiences of families of children younger than 4 years hospitalized for severe persistent asthma. The children who were African American or Latino and living in poverty were at highest risk of morbidity and mortality. Three families with distinctly varied responses to early symptoms were chosen from an investigation of 11 families for this study. Each gave three home interviews and participated in home observations. All families experienced life-changing responses to their children's distressed breathing. All had experienced asthma in themselves or others that shaped their beliefs and management patterns. Family experiences prior to and following diagnosis are discussed. Findings suggest that understanding these experiences and respecting families' earliest responses will help clarify established family management patterns for severe asthma in infants and toddlers and will enhance the ability of providers to guide the care of these families and children.

The characteristics and chronology of the earliest Acheulean at Konso, Ethiopia

PubMed Central

Beyene, Yonas; Katoh, Shigehiro; WoldeGabriel, Giday; Hart, William K.; Uto, Kozo; Sudo, Masafumi; Kondo, Megumi; Hyodo, Masayuki; Renne, Paul R.; Suwa, Gen; Asfaw, Berhane

2013-01-01

The Acheulean technological tradition, characterized by a large (>10 cm) flake-based component, represents a significant technological advance over the Oldowan. Although stone tool assemblages attributed to the Acheulean have been reported from as early as circa 1.6–1.75 Ma, the characteristics of these earliest occurrences and comparisons with later assemblages have not been reported in detail. Here, we provide a newly established chronometric calibration for the Acheulean assemblages of the Konso Formation, southern Ethiopia, which span the time period ∼1.75 to <1.0 Ma. The earliest Konso Acheulean is chronologically indistinguishable from the assemblage recently published as the world’s earliest with an age of ∼1.75 Ma at Kokiselei, west of Lake Turkana, Kenya. This Konso assemblage is characterized by a combination of large picks and crude bifaces/unifaces made predominantly on large flake blanks. An increase in the number of flake scars was observed within the Konso Formation handaxe assemblages through time, but this was less so with picks. The Konso evidence suggests that both picks and handaxes were essential components of the Acheulean from its initial stages and that the two probably differed in function. The temporal refinement seen, especially in the handaxe forms at Konso, implies enhanced function through time, perhaps in processing carcasses with long and stable cutting edges. The documentation of the earliest Acheulean at ∼1.75 Ma in both northern Kenya and southern Ethiopia suggests that behavioral novelties were being established in a regional scale at that time, paralleling the emergence of Homo erectus-like hominid morphology. PMID:23359714

Vertebral architecture in the earliest stem tetrapods.

PubMed

Pierce, Stephanie E; Ahlberg, Per E; Hutchinson, John R; Molnar, Julia L; Sanchez, Sophie; Tafforeau, Paul; Clack, Jennifer A

2013-02-14

The construction of the vertebral column has been used as a key anatomical character in defining and diagnosing early tetrapod groups. Rhachitomous vertebrae--in which there is a dorsally placed neural arch and spine, an anteroventrally placed intercentrum and paired, posterodorsally placed pleurocentra--have long been considered the ancestral morphology for tetrapods. Nonetheless, very little is known about vertebral anatomy in the earliest stem tetrapods, because most specimens remain trapped in surrounding matrix, obscuring important anatomical features. Here we describe the three-dimensional vertebral architecture of the Late Devonian stem tetrapod Ichthyostega using propagation phase-contrast X-ray synchrotron microtomography. Our scans reveal a diverse array of new morphological, and associated developmental and functional, characteristics, including a possible posterior-to-anterior vertebral ossification sequence and the first evolutionary appearance of ossified sternal elements. One of the most intriguing features relates to the positional relationships between the vertebral elements, with the pleurocentra being unexpectedly sutured or fused to the intercentra that directly succeed them, indicating a 'reverse' rhachitomous design. Comparison of Ichthyostega with two other stem tetrapods, Acanthostega and Pederpes, shows that reverse rhachitomous vertebrae may be the ancestral condition for limbed vertebrates. This study fundamentally revises our current understanding of vertebral column evolution in the earliest tetrapods and raises questions about the presumed vertebral architecture of tetrapodomorph fish and later, more crownward, tetrapods.

The reproductive biology and early life ecology of a common Caribbean brain coral, Diploria labyrinthiformis (Scleractinia: Faviinae)

NASA Astrophysics Data System (ADS)

Chamberland, Valérie F.; Snowden, Skylar; Marhaver, Kristen L.; Petersen, Dirk; Vermeij, Mark J. A.

2017-03-01

Despite the fact that most of the severe demographic bottlenecks in coral populations occur during their earliest life stages, information on the reproductive biology and early life history traits of many coral species is limited and often inferred from adult traits only. This study reports on several atypical aspects of the reproductive biology and early life ecology of the grooved brain coral, Diploria labyrinthiformis (Linnaeus, 1758), a conspicuous reef-building species on Caribbean reefs. The timing of gamete release of D. labyrinthiformis was monitored in Curaçao over eight consecutive months, and embryogenesis, planulae behavior, and settlement rates were observed and quantified. We further studied growth and symbiont acquisition in juvenile D. labyrinthiformis for 3.5 yr and compared settler survival under ambient and nutrient-enriched conditions in situ. Notably, D. labyrinthiformis reproduced during daylight hours in six consecutive monthly spawning events between May and September 2013, with a peak in June. This is the largest number of reproductive events per year ever observed in a broadcast-spawning Caribbean coral species. In settlement experiments, D. labyrinthiformis planulae swam to the bottom of culture containers 13 h after spawning and rapidly settled when provided with settlement cues (42% within 14 h). After 5 months, the survival and growth rates of settled juveniles were 3.7 and 1.9 times higher, respectively, for settlers that acquired zooxanthellae within 1 month after settlement, compared to those that acquired symbionts later on. Nutrient enrichment increased settler survival fourfold, but only for settlers that had acquired symbionts within 1 month after settlement. With at least six reproductive events per year, a short planktonic larval phase, high settlement rates, and a positive response to nutrient enrichment, the broadcast-spawning species D. labyrinthiformis displays a range of reproductive and early life-history traits that

Dietary specializations and diversity in feeding ecology of the earliest stem mammals.

PubMed

Gill, Pamela G; Purnell, Mark A; Crumpton, Nick; Brown, Kate Robson; Gostling, Neil J; Stampanoni, M; Rayfield, Emily J

2014-08-21

The origin and radiation of mammals are key events in the history of life, with fossils placing the origin at 220 million years ago, in the Late Triassic period. The earliest mammals, representing the first 50 million years of their evolution and including the most basal taxa, are widely considered to be generalized insectivores. This implies that the first phase of the mammalian radiation--associated with the appearance in the fossil record of important innovations such as heterodont dentition, diphyodonty and the dentary-squamosal jaw joint--was decoupled from ecomorphological diversification. Finds of exceptionally complete specimens of later Mesozoic mammals have revealed greater ecomorphological diversity than previously suspected, including adaptations for swimming, burrowing, digging and even gliding, but such well-preserved fossils of earlier mammals do not exist, and robust analysis of their ecomorphological diversity has previously been lacking. Here we present the results of an integrated analysis, using synchrotron X-ray tomography and analyses of biomechanics, finite element models and tooth microwear textures. We find significant differences in function and dietary ecology between two of the earliest mammaliaform taxa, Morganucodon and Kuehneotherium--taxa that are central to the debate on mammalian evolution. Morganucodon possessed comparatively more forceful and robust jaws and consumed 'harder' prey, comparable to extant small-bodied mammals that eat considerable amounts of coleopterans. Kuehneotherium ingested a diet comparable to extant mixed feeders and specialists on 'soft' prey such as lepidopterans. Our results reveal previously hidden trophic specialization at the base of the mammalian radiation; hence even the earliest mammaliaforms were beginning to diversify--morphologically, functionally and ecologically. In contrast to the prevailing view, this pattern suggests that lineage splitting during the earliest stages of mammalian evolution was

The initial (earliest) report of polymorphous ventricular tachycardia.

PubMed

Jani, Sonal; Schweitzer, Paul

2006-07-01

In these short historical notes, we describe the early history of polymorphic ventricular tachycardia. Polymorphous ventricular tachycardia was probably first noted in 1918 by Wilson and Robinson. In a publication describing complete heart block and ventriculophasic arrhythmia, they noted a tachyarrhythmia characterized by multiple extrasystoles of different types at a rapid rate. Also, we briefly discuss the earliest recognized torsades de pointes by Dessertenes in 1966 and the first description of catecholaminergic polymorphic ventricular tachycardia, by Reid in 1977.

Cacao usage by the earliest Maya civilization.

PubMed

Hurst, W Jeffrey; Tarka, Stanley M; Powis, Terry G; Valdez, Fred; Hester, Thomas R

2002-07-18

The Maya archaeological site at Colha in northern Belize, Central America, has yielded several spouted ceramic vessels that contain residues from the preparation of food and beverages. Here we analyse dry residue samples by using high-performance liquid chromatography coupled to atmospheric-pressure chemical-ionization mass spectrometry, and show that chocolate (Theobroma cacao) was consumed by the Preclassic Maya as early as 600 bc, pushing back the earliest chemical evidence of cacao use by some 1,000 years. Our application of this new and highly sensitive analytical technique could be extended to the identification of other ancient foods and beverages.

Archeological Investigations in the Truscott Reservoir Area. King and Knox Counties, Texas,

DTIC Science & Technology

1978-06-01

Roy Dickinson, Mr. John A. Kay, Mr. Benton Ross, and the staff of the Texas Highway Department District Headquarters of Wichita Falls for...of the earliest settlers in King County was Isom Lynn, who came there in 1877 with friends, John and Aaron Lasater, from Jack County. The Lasaters...J. W. Williams, "Some Northwest Texas Trails after Butterfield," West Texas Historical Association Year Book 42 (1966), pp. 78-79. 23. John R

Earliest evidence for arthrogryposis multiplex congenita or Larsen syndrome?

PubMed

Anderson, T

1997-08-08

A sixteenth-century illustrated pamphlet from Great Britain suggests that documentary evidence may permit accurate diagnosis of pathological conditions in earlier societies. The document is of particular importance, since the presented congenital abnormalities, including cleft lip, spina bifida cystica, genu recurvatum, and talipes deformity are reported rarely in archaeological skeletal material. It is suggested that the combination of abnormalities may represent the earliest case of arthrogryposis multiplex congenita or Larsen syndrome.

Settler colonial power and the American Indian sovereignty movement: forms of domination, strategies of transformation.

PubMed

Steinman, Erich

2012-01-01

The article extends the multi-institutional model of power and change through an analysis of the American Indian Sovereignty Movement. Drawing upon cultural models of the state, and articulating institutionalist conceptions of political opportunities and resources, the analysis demonstrates that this framework can be applied to challenges addressing the state as well as nonstate fields. The rational-legal diminishment of tribal rights, bureaucratic paternalism, commonsense views of tribes as racial/ethnic minorities, and the binary construction of American and Indian as oppositional identities diminished the appeal of "contentious" political action. Instead, to establish tribes' status as sovereign nations, tribal leaders aggressively enacted infrastructural power, transposed favorable legal rulings across social fields to legitimize sovereignty discourses, and promoted a pragmatic coexistence with state and local governments. Identifying the United States as a settler colonial society, the study suggests that a decolonizing framework is more apt than racial/ethnicity approaches in conceptualizing the struggle of American Indians.

Ornaments of the earliest Upper Paleolithic: New insights from the Levant

PubMed Central

Kuhn, Steven L.; Stiner, Mary C.; Reese, David S.; Güleç, Erksin

2001-01-01

Two sites located on the northern Levantine coast, Üçağızlı Cave (Turkey) and Ksar 'Akil (Lebanon) have yielded numerous marine shell beads in association with early Upper Paleolithic stone tools. Accelerator mass spectrometry (AMS) radiocarbon dates indicate ages between 39,000 and 41,000 radiocarbon years (roughly 41,000–43,000 calendar years) for the oldest ornament-bearing levels in Üçağızlı Cave. Based on stratigraphic evidence, the earliest shell beads from Ksar 'Akil may be even older. These artifacts provide some of the earliest evidence for traditions of personal ornament manufacture by Upper Paleolithic humans in western Asia, comparable in age to similar objects from Eastern Europe and Africa. The new data show that the initial appearance of Upper Paleolithic ornament technologies was essentially simultaneous on three continents. The early appearance and proliferation of ornament technologies appears to have been contingent on variable demographic or social conditions. PMID:11390976

The Faith of the Force: The Strategic Implications of Religion in the United States Air Force

DTIC Science & Technology

2012-06-01

human beings developing the capacity for telepathy through vibrations in molars. My wife told me it was the dumbest thing I’d ever said. While I am...vibrational telepathy . ABSTRACT This study examines the strategic implications of religion in the United States Air Force. While religion in the...version of the city on the hill analogy: “As the earliest settlers arrived on the shores of Boston and Salem and Plymouth, they dreamed of building a

Chemical and archaeological evidence for the earliest cacao beverages.

PubMed

Henderson, John S; Joyce, Rosemary A; Hall, Gretchen R; Hurst, W Jeffrey; McGovern, Patrick E

2007-11-27

Chemical analyses of residues extracted from pottery vessels from Puerto Escondido in what is now Honduras show that cacao beverages were being made there before 1000 B.C., extending the confirmed use of cacao back at least 500 years. The famous chocolate beverage served on special occasions in later times in Mesoamerica, especially by elites, was made from cacao seeds. The earliest cacao beverages consumed at Puerto Escondido were likely produced by fermenting the sweet pulp surrounding the seeds.

Earliest evidence for commensal processes of cat domestication.

PubMed

Hu, Yaowu; Hu, Songmei; Wang, Weilin; Wu, Xiaohong; Marshall, Fiona B; Chen, Xianglong; Hou, Liangliang; Wang, Changsui

2014-01-07

Domestic cats are one of the most popular pets globally, but the process of their domestication is not well understood. Near Eastern wildcats are thought to have been attracted to food sources in early agricultural settlements, following a commensal pathway to domestication. Early evidence for close human-cat relationships comes from a wildcat interred near a human on Cyprus ca. 9,500 y ago, but the earliest domestic cats are known only from Egyptian art dating to 4,000 y ago. Evidence is lacking from the key period of cat domestication 9,500-4,000 y ago. We report on the presence of cats directly dated between 5560-5280 cal B.P. in the early agricultural village of Quanhucun in Shaanxi, China. These cats were outside the wild range of Near Eastern wildcats and biometrically smaller, but within the size-range of domestic cats. The δ(13)C and δ(15)N values of human and animal bone collagen revealed substantial consumption of millet-based foods by humans, rodents, and cats. Ceramic storage containers designed to exclude rodents indicated a threat to stored grain in Yangshao villages. Taken together, isotopic and archaeological data demonstrate that cats were advantageous for ancient farmers. Isotopic data also show that one cat ate less meat and consumed more millet-based foods than expected, indicating that it scavenged among or was fed by people. This study offers fresh perspectives on cat domestication, providing the earliest known evidence for commensal relationships between people and cats.

Earliest evidence for commensal processes of cat domestication

PubMed Central

Hu, Yaowu; Hu, Songmei; Wang, Weilin; Wu, Xiaohong; Marshall, Fiona B.; Chen, Xianglong; Hou, Liangliang; Wang, Changsui

2014-01-01

Domestic cats are one of the most popular pets globally, but the process of their domestication is not well understood. Near Eastern wildcats are thought to have been attracted to food sources in early agricultural settlements, following a commensal pathway to domestication. Early evidence for close human–cat relationships comes from a wildcat interred near a human on Cyprus ca. 9,500 y ago, but the earliest domestic cats are known only from Egyptian art dating to 4,000 y ago. Evidence is lacking from the key period of cat domestication 9,500–4,000 y ago. We report on the presence of cats directly dated between 5560–5280 cal B.P. in the early agricultural village of Quanhucun in Shaanxi, China. These cats were outside the wild range of Near Eastern wildcats and biometrically smaller, but within the size-range of domestic cats. The δ13C and δ15N values of human and animal bone collagen revealed substantial consumption of millet-based foods by humans, rodents, and cats. Ceramic storage containers designed to exclude rodents indicated a threat to stored grain in Yangshao villages. Taken together, isotopic and archaeological data demonstrate that cats were advantageous for ancient farmers. Isotopic data also show that one cat ate less meat and consumed more millet-based foods than expected, indicating that it scavenged among or was fed by people. This study offers fresh perspectives on cat domestication, providing the earliest known evidence for commensal relationships between people and cats. PMID:24344279

Chemical and archaeological evidence for the earliest cacao beverages

PubMed Central

Henderson, John S.; Joyce, Rosemary A.; Hall, Gretchen R.; Hurst, W. Jeffrey; McGovern, Patrick E.

2007-01-01

Chemical analyses of residues extracted from pottery vessels from Puerto Escondido in what is now Honduras show that cacao beverages were being made there before 1000 B.C., extending the confirmed use of cacao back at least 500 years. The famous chocolate beverage served on special occasions in later times in Mesoamerica, especially by elites, was made from cacao seeds. The earliest cacao beverages consumed at Puerto Escondido were likely produced by fermenting the sweet pulp surrounding the seeds. PMID:18024588

Gathering Together: A View of the Earliest Student Affairs Professional Organizations

ERIC Educational Resources Information Center

Gerda, Janice J.

2006-01-01

In November 1903, 18 women gathered together for the Conference of Deans of Women of the Middle West. Variations of this conference were held over the following 20 years, constituting the earliest period of professional association in what was to become known as student affairs. When creating their associations, the early deans needed to consider…

Archaeometallurgical characterization of the earliest European metal helmets

PubMed Central

Mödlinger, Marianne; Piccardo, Paolo; Kasztovszky, Zsolt; Kovács, Imre; Szőkefalvi-Nagy, Zoltán; Káli, György; Szilágyi, Veronika

2013-01-01

Archaeometric analyses on conical and decorated cap helmets from the Bronze Age are presented. The helmets are dated to the 14–12th century BC according to associated finds in hoards. Alloy composition, material structure and manufacturing processes are determined and shed light on the earliest development of weaponry production in Central and Eastern Europe. Analyses were carried out using light and dark field microscopy, SEM–EDXS, PIXE, TOF-ND and PGAA. The results allowed reconstructing the manufacturing process, the differences between the cap of the helmets and their knobs (i.e. alloy composition) and the joining technique of the two parts. PMID:26523114

The earliest modern humans outside Africa.

PubMed

Hershkovitz, Israel; Weber, Gerhard W; Quam, Rolf; Duval, Mathieu; Grün, Rainer; Kinsley, Leslie; Ayalon, Avner; Bar-Matthews, Miryam; Valladas, Helene; Mercier, Norbert; Arsuaga, Juan Luis; Martinón-Torres, María; Bermúdez de Castro, José María; Fornai, Cinzia; Martín-Francés, Laura; Sarig, Rachel; May, Hila; Krenn, Viktoria A; Slon, Viviane; Rodríguez, Laura; García, Rebeca; Lorenzo, Carlos; Carretero, Jose Miguel; Frumkin, Amos; Shahack-Gross, Ruth; Bar-Yosef Mayer, Daniella E; Cui, Yaming; Wu, Xinzhi; Peled, Natan; Groman-Yaroslavski, Iris; Weissbrod, Lior; Yeshurun, Reuven; Tsatskin, Alexander; Zaidner, Yossi; Weinstein-Evron, Mina

2018-01-26

To date, the earliest modern human fossils found outside of Africa are dated to around 90,000 to 120,000 years ago at the Levantine sites of Skhul and Qafzeh. A maxilla and associated dentition recently discovered at Misliya Cave, Israel, was dated to 177,000 to 194,000 years ago, suggesting that members of the Homo sapiens clade left Africa earlier than previously thought. This finding changes our view on modern human dispersal and is consistent with recent genetic studies, which have posited the possibility of an earlier dispersal of Homo sapiens around 220,000 years ago. The Misliya maxilla is associated with full-fledged Levallois technology in the Levant, suggesting that the emergence of this technology is linked to the appearance of Homo sapiens in the region, as has been documented in Africa. Copyright © 2018, The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Earliest Memories and Recent Memories of Highly Salient Events--Are They Similar?

ERIC Educational Resources Information Center

Peterson, Carole; Fowler, Tania; Brandeau, Katherine M.

2015-01-01

Four- to 11-year-old children were interviewed about 2 different sorts of memories in the same home visit: recent memories of highly salient and stressful events--namely, injuries serious enough to require hospital emergency room treatment--and their earliest memories. Injury memories were scored for amount of unique information, completeness…

The Earliest Ion Channels in Protocellular Membranes

NASA Technical Reports Server (NTRS)

Mijajlovic, Milan; Pohorille, Andrew; Wilson, Michael; Wei, Chenyu

2010-01-01

Cellular membranes with their hydrophobic interior are virtually impermeable to ions. Bulk of ion transport through them is enabled through ion channels. Ion channels of contemporary cells are complex protein molecules which span the membrane creating a cylindrical pore filled with water. Protocells, which are widely regarded as precursors to modern cells, had similarly impermeable membranes, but the set of proteins in their disposal was much simpler and more limited. We have been, therefore, exploring an idea that the first ion channels in protocellular membranes were formed by much smaller peptide molecules that could spontaneously selfassemble into short-lived cylindrical bundles in a membrane. Earlier studies have shown that a group of peptides known as peptaibols is capable of forming ion channels in lipid bilayers when they are exposed to an electric field. Peptaibols are small, non-genetically encoded peptides produced by some fungi as a part of their system of defense against bacteria. They are usually only 14-20 residues long, which is just enough to span the membrane. Their sequence is characterized by the presence of non-standard amino acids which, interestingly, are also expected to have existed on the early earth. In particular, the presence of 2-aminoisobutyric acid (AIB) gives peptaibols strong helix forming propensities. Association of the helices inside membranes leads to the formation of cylindrical bundles, typically containing 4 to 10 monomers. Although peptaibols are excellent candidates for models of the earliest ion channels their structures, which are stabilized only by van der Waals forces and occasional hydrogen bonds between neighboring helices, are not very stable. Although it might properly reflect protobiological reality, it is also a major obstacle in studying channel behavior. For this reason we focused on two members of the peptaibol family, trichotoxin and antiamoebin, which are characterized by a single conductance level. This

The earliest ion channels in protocellular membranes

NASA Astrophysics Data System (ADS)

Mijajlovic, Milan; Pohorille, Andrew; Wilson, Michael; Wei, Chenyu

Cellular membranes with their hydrophobic interior are virtually impermeable to ions. Bulk of ion transport through them is enabled through ion channels. Ion channels of contemporary cells are complex protein molecules which span the membrane creating a cylindrical pore filled with water. Protocells, which are widely regarded as precursors to modern cells, had similarly impermeable membranes, but the set of proteins in their disposal was much simpler and more limited. We have been, therefore, exploring an idea that the first ion channels in protocellular membranes were formed by much smaller peptide molecules that could spontaneously self-assemble into short-lived cylindrical bundles in a membrane. Earlier studies have shown that a group of peptides known as peptaibols is capable of forming ion channels in lipid bilayers when they are exposed to an electric field. Peptaibols are small, non-genetically encoded peptides produced by some fungi as a part of their system of defense against bacteria. They are usually only 14-20 residues long, which is just enough to span the membrane. Their sequence is characterized by the presence of non-standard amino acids which, interestingly, are also expected to have existed on the early earth. In particular, the presence of 2-aminoisobutyric acid (AIB) gives peptaibols strong helix forming propensities. Association of the helices inside membranes leads to the formation of cylindrical bundles, typically containing 4 to 10 monomers. Although peptaibols are excellent candidates for models of the earliest ion channels their struc-tures, which are stabilized only by van der Waals forces and occasional hydrogen bonds between neighboring helices, are not very stable. Although it might properly reflect protobiological real-ity, it is also a major obstacle in studying channel behavior. For this reason we focused on two members of the peptaibol family, trichotoxin and antiamoebin, which are characterized by a single conductance level. This

Considerations on Terrestrial Iron Depositing Analogs to Earliest Mars

NASA Technical Reports Server (NTRS)

Brown, Igor I.; Allen, Carlton C.; Sarkisova, S. A.; Garrison, D. H.; McKay, D. S.

2007-01-01

Iron oxide and hydroxide minerals, including hematite, can mineralize and preservemicrofossils and physical biomarkers (Allen at al., 2004). Preserved remnants of phototrophic microorganisms are recognized as biosignatures of past life on Earth (Schopf, 2006). To date, two types of surface iron depositing environments have been studied as analogs to possible habitable environments on earliest Mars: the highly acidified Rio Tinto River (Iberian Belt, Spain) [Gomez Ortis et al., 2007], and the nearneutral iron depositing Chocolate Pots Hot Spring (Yellowstone National Park, US) [Parenteau at al., 2005]. While phototrophs in the Rio Tinto are only represented by eukaryotic algae (Amaral Zettler et all., 2002), Chocolate Pots is mainly populated with cyanobacteria (Pierson et all., 2000; Brown et all., 2007). Which of these environments is the closer analog to a potentially habitable early Mars? Paleobiological data, combined with recent "tree of life" interpretations, suggest that phototrophic eukaryotes evolved not earlier than 2.5 - 2.8 b.y. after Earth s accretion (4.6 b.y.), while cyanobacteria and /or their iron-tolerant predecessors evolved between 1 - 1.5 b.y. after accretion (Brown et al., 2007). Lindsay and Brasier (2002) postulated that microbial life on Mars surface could have lasted no more than 1-1.5 b.y. after Mars accretion (also 4.6 b.y.). Recent multispectral mapping of Mars suggests that near-neutral wet environments prevailed at approximately this time (Bibring, et al., 2006). Thus, near-neutral iron depositing hot springs such as Chocolate Pots Hot Spring seem to be the more likely habitable analogs for earliest Mars.

The earliest modern mongoose (Carnivora, Herpestidae) from Africa (late Miocene of Chad)

NASA Astrophysics Data System (ADS)

Peigné, Stéphane; Bonis, Louis; Likius, Andossa; Mackaye, Hassane Taïsso; Vignaud, Patrick; Brunet, Michel

2005-06-01

We report on the earliest modern mongooses of Africa, from the late Miocene (ca. 7 Ma) of the hominid locality TM 266, Toros-Menalla, Chad. The material is based on fragmentary dentitions of three individuals. The main diagnostic feature of the Chadian species is the great development of the shear in the carnassials, which distinguishes the Chadian specimens from all extant herpestids except Herpestes and Galerella. In comparison with most extinct and extant Herpestes, the species from Toros-Menalla differs by a markedly smaller size and, depending on the species, relatively more elongated carnassials, more transversely elongated M1 and more reduced p4. On the basis of a great morphological similarity and the absence of significant differences, we assign our material to Galerella sanguinea; the Chadian finding therefore represents the earliest appearance of an extant species of Herpestidae. This record ties the first appearance of the genus to a minimum age of ca. 7 Ma, which is consistent with the estimated divergence date of 11.4 Ma known from the literature for the species of Galerella.

The earliest modern mongoose (Carnivora, Herpestidae) from Africa (late Miocene of Chad).

PubMed

Peigné, Stéphane; de Bonis, Louis; Likius, Andossa; Mackaye, Hassane Taïsso; Vignaud, Patrick; Brunet, Michel

2005-06-01

We report on the earliest modern mongooses of Africa, from the late Miocene (ca. 7 Ma) of the hominid locality TM 266, Toros-Menalla, Chad. The material is based on fragmentary dentitions of three individuals. The main diagnostic feature of the Chadian species is the great development of the shear in the carnassials, which distinguishes the Chadian specimens from all extant herpestids except Herpestes and Galerella. In comparison with most extinct and extant Herpestes, the species from Toros-Menalla differs by a markedly smaller size and, depending on the species, relatively more elongated carnassials, more transversely elongated M1 and more reduced p4. On the basis of a great morphological similarity and the absence of significant differences, we assign our material to Galerella sanguinea; the Chadian finding therefore represents the earliest appearance of an extant species of Herpestidae. This record ties the first appearance of the genus to a minimum age of ca. 7 Ma, which is consistent with the estimated divergence date of 11.4 Ma known from the literature for the species of Galerella.

Maternal Reminiscing Style during Early Childhood Predicts the Age of Adolescents' Earliest Memories

ERIC Educational Resources Information Center

Jack, Fiona; MacDonald, Shelley; Reese, Elaine; Hayne, Harlene

2009-01-01

Individual differences in parental reminiscing style are hypothesized to have long-lasting effects on children's autobiographical memory development, including the age of their earliest memories. This study represents the first prospective test of this hypothesis. Conversations about past events between 17 mother-child dyads were recorded on…

Experiencing patient death in clinical practice: nurses' recollections of their earliest memorable patient death.

PubMed

Anderson, Natalie Elizabeth; Kent, Bridie; Owens, R Glynn

2015-03-01

Death and dying are inevitable life encounters, but a nurse's first experience with patient death may pose considerable cognitive, emotional and clinical challenges. This paper reports the findings of the second phase of a study; the first has been reported elsewhere. This phase explored the earliest memorable patient death experiences of New Zealand registered nurses. A purposeful, self-selected sub-sample of a larger study of New Zealand registered nurses, took part in individual face-to-face semi-structured interviews. Interpretative phenomenological analysis was utilised to seek to understand participants' experiences. Thematic analysis was undertaken to identify emerging themes, with participants' own words used as theme headings, where their phrases provided succinct or powerful descriptors. A diverse participant group of twenty, currently practising, New Zealand registered nurses provided rich and detailed descriptions of their earliest memorable experience with patient death. Participants from a variety of training backgrounds described patient deaths, which occurred in a range of settings - some only a few months prior, others - more than thirty years ago. Seven emergent themes, and features of more positive, or negative experiences were identified: Event Significance; Emotional Challenges; Sharing the Experience; Learning; Feeling Unprepared, Responses to Death and Finding Benefits. For participants in this study, there was considerable evidence that their earliest memorable patient death was a significant event. Furthermore, although most participants' experiences were characterised by emphatic or poignant description, there was most often a balance of challenges and rewards. Copyright © 2014 Elsevier Ltd. All rights reserved.

Monitoring efficacy of commonly used antimalarials by a 14-day in-vivo test in a new settler's camp in endemic zone at Cox's Bazar.

PubMed

Rahman, M R; Hassan, M R; Faiz, M A; Samad, R; Paul, B; Jalil, M A

1998-12-01

The study was done in a new settler's camp "Barachara" under Sadar thana of Cox's Bazar district. It has a total population of 784 of all age groups, registered in the middle of the study period. A prospective evaluation of all cases of fever were done over 12 months, to see the pattern of febrile illness among the population and to compare the therapeutic efficacy of two alternative drug regimens for uncomplicated falciparum malaria (UM). Blood for malarial parasite (MP) was done in all cases of fever and was treated in line with the new clinical case definitions and treatment guidelines for malaria in Bangladesh. Slide positive UM cases were subjected to a "14-day in-vivo test" for therapeutic efficacy testing of antimalarial agents. The two drug regimens were randomised by lottery--a) 3 days oral chloroquine plus single dose sulphadoxin/pyrimethamine (CQ + SP) and, b) 3 days oral quinine plus single dose sulphadoxin/pyrimethamine (Q3 + SP). Drug administration was supervised by the field assistant and was followed up on days 3, 7 and 14 for blood slide examinations and clinical assessment. Sensitive response was observed in 79% of the cases in the CQ + SP group and 84% in the Q3 + SP group. Early treatment failure (persistently febrile and parasitaemic on days 3 or 7) was observed in 16% in the CQ + SP group and 9% in the Q3 + SP group. Both the evaluated drug regimens had less than 20% failures and can be used as alternative first line agents and Q3 + SP regimens can also be used as the second line agents for treatment failure (to chloroquine and/or SP) UM cases in the study area.

Medication persistence and discontinuation of rivaroxaban versus warfarin among patients with non-valvular atrial fibrillation.

PubMed

Nelson, Winnie W; Song, Xue; Coleman, Craig I; Thomson, Erin; Smith, David M; Damaraju, C V; Schein, Jeffrey R

2014-12-01

To compare real-world persistence and discontinuation among non-valvular atrial fibrillation (NVAF) patients on rivaroxaban and warfarin in the US. A large nationally representative US claims database was used to conduct a retrospective cohort analysis of patients with NVAF treated with rivaroxaban or warfarin from 1 July 2010 through 31 March 2013. Index date was the date of the first prescription of rivaroxaban or warfarin. All patients were followed until the earliest of inpatient death, end of continuous enrollment, or end of study period. Rivaroxaban patients were matched 1:1 by propensity scores. Medication persistence was defined as absence of refill gap of ≥ 60 days. Discontinuation was defined as no additional refill for at least 90 days and until the end of follow-up. Cox proportional hazards models were estimated to examine the adjusted hazard ratios (aHRs) of rivaroxaban vs. warfarin on non-persistence and discontinuation. A total of 32,886 NVAF patients on rivaroxaban or warfarin met the study inclusion criteria. Each of the 7259 rivaroxaban patients identified were matched 1:1 to warfarin patients. Patients on rivaroxaban had a significantly better rate of persistence (aHR: 0.63, 95% CI 0.59-0.68) and lower rate of discontinuation (aHR: 0.54, 95% CI 0.49-0.58) compared to warfarin recipients. Claims data may have contained inaccuracies and miscoding. Confounding may remain even after propensity score matching and additional adjustments in model. Refill data may not fully reflect actual medication use. Longer follow-up may produce more precise estimates of persistence and discontinuation. This matched cohort analysis indicated that rivaroxaban was associated with significantly higher medication persistence and lower discontinuation rates compared to warfarin.

The earliest direct evidence of frogs in wet tropical forests from Cretaceous Burmese amber.

PubMed

Xing, Lida; Stanley, Edward L; Bai, Ming; Blackburn, David C

2018-06-14

Frogs are a familiar and diverse component of tropical forests around the world. Yet there is little direct evidence from the fossil record for the antiquity of this association. We describe four fossil frog specimens from mid-Cretaceous (~99 mya) amber deposits from Kachin State, Myanmar for which the associated fauna provides rich paleoenvironmental context. Microcomputed tomographic analysis provides detailed three-dimensional anatomy for these small frogs, which is generally unavailable for articulated anurans in the Mesozoic. These crown-group anuran specimens provide the earliest direct evidence for anurans in a wet tropical forest. Based on a distinct combination of skeletal characters, at least one specimen has clear similarities to living alytoid frogs as well as several Mesozoic taxa known from the Jehol Biota in China. Whereas many Mesozoic frogs are from seasonal and mesic paleoenvironments, these fossils provide the earliest direct evidence of anurans in wet tropical forests.

Birth to Three Matters: A Framework to Support Children in Their Earliest Years

ERIC Educational Resources Information Center

Abbott, Lesley; Langston, Ann

2005-01-01

Government commitment to the care and education of children from birth to three years in England led to the commissioning in 2001 of "a framework of best practice" (DfEE, 2001:24) to support children in their earliest years. The resulting framework of "effective" practice, together with supporting materials, was developed by a…

Virtual endocranial cast of earliest Eocene Diacodexis (Artiodactyla, Mammalia) and morphological diversity of early artiodactyl brains

PubMed Central

Orliac, M. J.; Gilissen, E.

2012-01-01

The study of brain evolution, particularly that of the neocortex, is of primary interest because it directly relates to how behavioural variations arose both between and within mammalian groups. Artiodactyla is one of the most diverse mammalian clades. However, the first 10 Myr of their brain evolution has remained undocumented so far. Here, we used high-resolution X-ray computed tomography to investigate the endocranial cast of Diacodexis ilicis of earliest Eocene age. Its virtual reconstruction provides unprecedented access to both metric parameters and fine anatomy of the most complete endocast of the earliest artiodactyl. This picture is assessed in a broad comparative context by reconstructing endocasts of 14 other Early and Middle Eocene representatives of basal artiodactyls, allowing the tracking of the neocortical structure of artiodactyls back to its simplest pattern. We show that the earliest artiodactyls share a simple neocortical pattern, so far never observed in other ungulates, with an almond-shaped gyrus instead of parallel sulci as previously hypothesized. Our results demonstrate that artiodactyls experienced a tardy pulse of encephalization during the Late Neogene, well after the onset of cortical complexity increase. Comparisons with Eocene perissodactyls show that the latter reached a high level of cortical complexity earlier than the artiodactyls. PMID:22764165

Medication persistence and discontinuation of rivaroxaban and dabigatran etexilate among patients with non-valvular atrial fibrillation.

PubMed

Nelson, Winnie W; Song, Xue; Thomson, Erin; Smith, David M; Coleman, Craig I; Damaraju, C V; Schein, Jeffrey R

2015-01-01

To compare real-world persistence and discontinuation among non-valvular atrial fibrillation (NVAF) patients on rivaroxaban and dabigatran in the US. A large nationally representative US claims database was used to conduct a retrospective cohort analysis of patients with NVAF on rivaroxaban or dabigatran between October 2010 and March 2013. The index date was the date of the first prescription of rivaroxaban or dabigatran. All patients had ≥6 months of data prior to the index date and were followed until the earliest of inpatient death, end of continuous enrollment, or end of the study period. Rivaroxaban patients were matched 1:1 with dabigatran patients using the propensity score matching technique. Cox proportional hazards models were employed to estimate the adjusted hazard ratios (aHRs) of non-persistence and discontinuation. Persistence was defined as absence of a refill gap of ≥60 days. Discontinuation was defined as no additional refill for at least 90 days and until the end of follow-up. A total of 30,337 NVAF patients on rivaroxaban or dabigatran met the study criteria. All 7259 rivaroxaban patients were matched 1:1 to dabigatran patients. Compared with dabigatran users, rivaroxaban patients were 11% less likely to become non-persistent with therapy (aHR: 0.89, 95% CI 0.84-0.95) and 29% less likely to discontinue therapy (aHR: 0.71, 95% CI 0.66-0.77). Claims data are subject to miscoding and inaccuracies. Refill data may not fully reflect actual medication taken. Confounding may remain even after propensity score matching and additional adjustments in model. Longer follow-up may produce more precise estimates of persistence and discontinuation. This matched cohort analysis indicated that, compared to dabigatran, rivaroxaban was associated with better persistence and lower rates of discontinuation.

Earliest Mexican Turkeys (Meleagris gallopavo) in the Maya Region: Implications for Pre-Hispanic Animal Trade and the Timing of Turkey Domestication

PubMed Central

Thornton, Erin Kennedy; Emery, Kitty F.; Steadman, David W.; Speller, Camilla; Matheny, Ray; Yang, Dongya

2012-01-01

Late Preclassic (300 BC–AD 100) turkey remains identified at the archaeological site of El Mirador (Petén, Guatemala) represent the earliest evidence of the Mexican turkey (Meleagris gallopavo) in the ancient Maya world. Archaeological, zooarchaeological, and ancient DNA evidence combine to confirm the identification and context. The natural pre-Hispanic range of the Mexican turkey does not extend south of central Mexico, making the species non-local to the Maya area where another species, the ocellated turkey (Meleagris ocellata), is indigenous. Prior to this discovery, the earliest evidence of M. gallopavo in the Maya area dated to approximately one thousand years later. The El Mirador specimens therefore represent previously unrecorded Preclassic exchange of animals from northern Mesoamerica to the Maya cultural region. As the earliest evidence of M. gallopavo found outside its natural geographic range, the El Mirador turkeys also represent the earliest indirect evidence for Mesoamerican turkey rearing or domestication. The presence of male, female and sub-adult turkeys, and reduced flight morphology further suggests that the El Mirador turkeys were raised in captivity. This supports an argument for the origins of turkey husbandry or at least captive rearing in the Preclassic. PMID:22905156

Earliest Mexican Turkeys (Meleagris gallopavo) in the Maya Region: implications for pre-Hispanic animal trade and the timing of turkey domestication.

PubMed

Thornton, Erin Kennedy; Emery, Kitty F; Steadman, David W; Speller, Camilla; Matheny, Ray; Yang, Dongya

2012-01-01

Late Preclassic (300 BC-AD 100) turkey remains identified at the archaeological site of El Mirador (Petén, Guatemala) represent the earliest evidence of the Mexican turkey (Meleagris gallopavo) in the ancient Maya world. Archaeological, zooarchaeological, and ancient DNA evidence combine to confirm the identification and context. The natural pre-Hispanic range of the Mexican turkey does not extend south of central Mexico, making the species non-local to the Maya area where another species, the ocellated turkey (Meleagris ocellata), is indigenous. Prior to this discovery, the earliest evidence of M. gallopavo in the Maya area dated to approximately one thousand years later. The El Mirador specimens therefore represent previously unrecorded Preclassic exchange of animals from northern Mesoamerica to the Maya cultural region. As the earliest evidence of M. gallopavo found outside its natural geographic range, the El Mirador turkeys also represent the earliest indirect evidence for Mesoamerican turkey rearing or domestication. The presence of male, female and sub-adult turkeys, and reduced flight morphology further suggests that the El Mirador turkeys were raised in captivity. This supports an argument for the origins of turkey husbandry or at least captive rearing in the Preclassic.

Origin and radiation of the earliest vascular land plants.

PubMed

Steemans, Philippe; Hérissé, Alain Le; Melvin, John; Miller, Merrell A; Paris, Florentin; Verniers, Jacques; Wellman, Charles H

2009-04-17

Colonization of the land by plants most likely occurred in a stepwise fashion starting in the Mid-Ordovician. The earliest flora of bryophyte-like plants appears to have been cosmopolitan and dominated the planet, relatively unchanged, for some 30 million years. It is represented by fossilized dispersed cryptospores and fragmentary plant remains. In the Early Silurian, cryptospore abundance and diversity diminished abruptly as trilete spores appeared, became abundant, and underwent rapid diversification. This change coincides approximately with the appearance of vascular plant megafossils and probably represents the origin and adaptive radiation of vascular plants. We have obtained a diverse trilete spore occurrence from the Late Ordovician that suggests that vascular plants originated and diversified earlier than previously hypothesized, in Gondwana, before migrating elsewhere and secondarily diversifying.

Observing the Earliest Galaxies: Looking for the Sources of Reionization

NASA Astrophysics Data System (ADS)

Illingworth, Garth

2015-04-01

Systematic searches for the earliest galaxies in the reionization epoch finally became possible in 2009 when the Hubble Space Telescope was updated with a powerful new infrared camera during the final Shuttle servicing mission SM4 to Hubble. The reionization epoch represents the last major phase transition of the universe and was a major event in cosmic history. The intense ultraviolet radiation from young star-forming galaxies is increasingly considered to be the source of the photons that reionized intergalactic hydrogen in the period between the ``dark ages'' (the time before the first stars and galaxies at about 100-200 million years after the Big Bang) and the end of reionization around 800-900 million years. Yet finding and measuring the earliest galaxies in this era of cosmic dawn has proven to a challenging task, even with Hubble's new infrared camera. I will discuss the deep imaging undertaken by Hubble and the remarkable insights that have accrued from the imaging datasets taken over the last decade on the Hubble Ultra-Deep Field (HUDF, HUDF09/12) and other regions. The HUDF datasets are central to the story and have been assembled into the eXtreme Deep Field (XDF), the deepest image ever from Hubble data. The XDF, when combined with results from shallower wide-area imaging surveys (e.g., GOODS, CANDELS) and with detections of galaxies from the Frontier Fields, has provided significant insights into the role of galaxies in reionization. Yet many questions remain. The puzzle is far from being fully solved and, while much will done over the next few years, the solution likely awaits the launch of JWST. NASA/STScI Grant HST-GO-11563.

The earliest history of diaphragm physiology.

PubMed

Derenne, J P; Debru, A; Grassino, A E; Whitelaw, W A

1994-12-01

The diaphragm was recognized as a distinct anatomical structure in the earliest Greek writings. However, the precise description of wounds suffered by warriors during the Trojan war by Homer was not tied to any particular function. The diaphragm was assimilated to the region that harbours thought. The first physiologic explanations of respiration by Empedocles in the 5th century BC and the concepts introduced by Plato and Hippocrates did not include a significant participation of the diaphragm. Aristole was the first to link respiration to a particular organ and a specific movement of the thorax. However, he considered that it was the heart which caused the lungs to expand by heating them, and the lungs in turn forced the thorax to dilate, a concept which was to survive until the 17th century. As in Aristole's theory the diaphragm played no role in respiration and was just a fence separating the thorax from the abdomen. A major break through occurred in Alexandria in the 4th and 3rd century BC: Herophilus was the first to recognize that muscles were the agents of movement and Erasistratus performed animal experiments which showed that the respiratory muscles were the agents of respiratory movements, thus opening the way to the later discoveries of Galen.

Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago

NASA Astrophysics Data System (ADS)

Eichler, A.; Gramlich, G.; Kellerhals, T.; Tobler, L.; Rehren, Th.; Schwikowski, M.

2017-01-01

The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200-800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700-50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures.

Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago.

PubMed

Eichler, A; Gramlich, G; Kellerhals, T; Tobler, L; Rehren, Th; Schwikowski, M

2017-01-31

The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200-800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700-50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures.

Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago

PubMed Central

Eichler, A.; Gramlich, G.; Kellerhals, T.; Tobler, L.; Rehren, Th.; Schwikowski, M.

2017-01-01

The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200–800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700–50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures. PMID:28139760

Earliest signs of life on land preserved in ca. 3.5 Ga hot spring deposits

PubMed Central

Djokic, Tara; Van Kranendonk, Martin J.; Campbell, Kathleen A.; Walter, Malcolm R.; Ward, Colin R.

2017-01-01

The ca. 3.48 Ga Dresser Formation, Pilbara Craton, Western Australia, is well known for hosting some of Earth’s earliest convincing evidence of life (stromatolites, fractionated sulfur/carbon isotopes, microfossils) within a dynamic, low-eruptive volcanic caldera affected by voluminous hydrothermal fluid circulation. However, missing from the caldera model were surface manifestations of the volcanic-hydrothermal system (hot springs, geysers) and their unequivocal link with life. Here we present new discoveries of hot spring deposits including geyserite, sinter terracettes and mineralized remnants of hot spring pools/vents, all of which preserve a suite of microbial biosignatures indicative of the earliest life on land. These include stromatolites, newly observed microbial palisade fabric and gas bubbles preserved in inferred mineralized, exopolymeric substance. These findings extend the known geological record of inhabited terrestrial hot springs on Earth by ∼3 billion years and offer an analogue in the search for potential fossil life in ancient Martian hot springs. PMID:28486437

Auxosporulation in Paralia guyana MacGillivary (Bacillariophyta) and Possible New Insights into the Habit of the Earliest Diatoms

PubMed Central

Kaczmarska, Irena; Ehrman, James M.

2015-01-01

Background Diatoms are one of the most ecologically important aquatic micro-eukaryotes. As a group unambiguously recognized as diatoms, they seem to have appeared relatively recently with a limited record of putative remains from oldest sediments. In contrast, molecular clock estimates for the earliest possible emergence of diatoms suggest a considerably older date. Depending on the analysis, Paralia and Leptocylindrus have been recovered within the basal molecular divergences of diatoms. Thus these genera may be in the position to inform on characters that the earliest diatoms possessed. Findings Here we present auxospore development and structure of initial and post-auxospore cells in a representative of the ancient non-polar centric genus Paralia. Their initial frustules showed unusual, but not unprecedented, spore-like morphology. Similarly, initial frustules of Leptocylindrus have been long considered resting spores and a unique peculiarity of this genus. However, even though spore-like in appearance, initial cells of Paralia readily resumed mitotic divisions. In addition, Paralia post-auxospore cells underwent several rounds of mitoses in a multi-step process of building a typical, “perfect” vegetative valve. This degree of heteromorphy immediately post-auxosporulation is thus far unknown among the diatoms. Implications A spore-related origin of diatoms has already been considered, most recently in the form of the “multiplate diploid cyst” hypothesis. Our discovery that the initial cells in some of the most ancient diatom lineages are structurally spore-like is consistent with that hypothesis because the earliest diatoms may be expected to look somewhat similar to their ancestors. We speculate that because the earliest diatoms may have appeared less diatom-like and more spore-like, they could have gone unrecognized as such in the Triassic/Jurassic sediments. If correct, diatoms may indeed be much older than the fossil record indicates, and possibly

Historically White Universities and Plantation Politics: Anti-Blackness and Higher Education in the Black Lives Matter Era

ERIC Educational Resources Information Center

Dancy, T. Elon, II; Edwards, Kirsten T.; Earl Davis, James

2018-01-01

In this article, the authors argue that U.S. colleges and universities must grapple with persistent engagements of Black bodies as property. Engaging the research and scholarship on Black faculty, staff, and students, we explain how theorizations of settler colonialism and anti-Blackness (re)interpret the arrangement between historically White…

New evidence on the anatomy and phylogeny of the earliest vertebrates.

PubMed Central

Xian-guang, Hou; Aldridge, Richard J; Siveter, David J; Siveter, Derek J; Xiang-hong, Feng

2002-01-01

We report the discovery of a new agnathan specimen from the Lower Cambrian Chengjiang Lagerstätte of China and thereby provide new evidence on the myomeres (V-shaped), the branchial apparatus (gill filaments and arches), the dorsal fin and the gonads (24-26) of the earliest vertebrates. The new specimen and the co-occurring Myllokunmingia fengjiaoa and Haikouichthys ercaicunensis represent a single species, which is a primitive member of the crown group craniates (vertebrates) and post-dates the origin of the myxinoids (hagfish). The origin of the vertebrate clade is at least as old as Early Cambrian. PMID:12350247

The earliest bird-line archosaurs and the assembly of the dinosaur body plan.

PubMed

Nesbitt, Sterling J; Butler, Richard J; Ezcurra, Martín D; Barrett, Paul M; Stocker, Michelle R; Angielczyk, Kenneth D; Smith, Roger M H; Sidor, Christian A; Niedźwiedzki, Grzegorz; Sennikov, Andrey G; Charig, Alan J

2017-04-27

The relationship between dinosaurs and other reptiles is well established, but the sequence of acquisition of dinosaurian features has been obscured by the scarcity of fossils with transitional morphologies. The closest extinct relatives of dinosaurs either have highly derived morphologies or are known from poorly preserved or incomplete material. Here we describe one of the stratigraphically lowest and phylogenetically earliest members of the avian stem lineage (Avemetatarsalia), Teleocrater rhadinus gen. et sp. nov., from the Middle Triassic epoch. The anatomy of T. rhadinus provides key information that unites several enigmatic taxa from across Pangaea into a previously unrecognized clade, Aphanosauria. This clade is the sister taxon of Ornithodira (pterosaurs and birds) and shortens the ghost lineage inferred at the base of Avemetatarsalia. We demonstrate that several anatomical features long thought to characterize Dinosauria and dinosauriforms evolved much earlier, soon after the bird-crocodylian split, and that the earliest avemetatarsalians retained the crocodylian-like ankle morphology and hindlimb proportions of stem archosaurs and early pseudosuchians. Early avemetatarsalians were substantially more species-rich, widely geographically distributed and morphologically diverse than previously recognized. Moreover, several early dinosauromorphs that were previously used as models to understand dinosaur origins may represent specialized forms rather than the ancestral avemetatarsalian morphology.

Infantile Amnesia across the Years: A 2-Year Follow-Up of Children's Earliest Memories

ERIC Educational Resources Information Center

Peterson, Carole; Warren, Kelly L.; Short, Megan M.

2011-01-01

Although infantile amnesia has been investigated for many years in adults, only recently has it been investigated in children. This study was a 2-year follow-up and extension of an earlier study. Children (4-13 years old) were asked initially and 2 years later for their earliest 3 memories. At follow-up, their age at the time of these memories…

Epidemiology of cutaneous leishmaniasis in central Amazonia: a comparison of sex-biased incidence among rural settlers and field biologists.

PubMed

Soares, Letícia; Abad-Franch, Fernando; Ferraz, Gonçalo

2014-08-01

Cutaneous leishmaniasis (CL) is more frequently reported in men than in women; this may be due to male-biased exposure to CL vectors, female-biased resistance against the disease or both. We sought to determine whether gender-specific exposure to vector habitats explains male-biased CL incidence in two human populations of central Amazonia. We compared the CL incidence in one population of field researchers (N = 166), with similar exposure for males and females, and one population of rural settlers (N = 646), where exposure is overall male-biased. We used a combination of questionnaires and clinical data to quantify CL cases, and modelled disease incidence in a Bayesian framework. There was a moderately higher incidence of CL among men than among women in both populations, but male bias decreased as exposure time increased. Disease incidence was overall higher among field researchers, suggesting that they are an important but understudied CL risk group. Our comparison of two contrasting populations provided epidemiological evidence that CL incidence can be male-biased even when exposure is comparable in both sexes. © 2014 John Wiley & Sons Ltd.

The earliest fossil evidence for sexual dimorphism in primates

NASA Technical Reports Server (NTRS)

Krishtalka, Leonard; Stucky, Richard K.; Beard, K. C.

1990-01-01

Recently obtained material of the early Eocene primate Notharctus venticolus, including two partial skulls from a single stratigraphic horizon, provides the geologically earliest evidence of sexual dimorphism in canine size and shape in primates and the only unequivocal evidence for such dimorphism in strepsirhines. By analogy with living platyrrhines, these data suggest that Notharctus venticolus may have lived in polygynous social groups characterized by a relatively high level of intermale competition for mates and other limited resources. The anatomy of the upper incisors and related evidence imply that Notharctus is not as closely related to extant lemuriform primates as has been recently proposed. The early Eocene evidence for canine sexual dimorphism reported here, and its occurrence in a nonanthropoid, indicates that in the order Primates such a condition is either primitive or evolved independently more than once.

Ultrasonic hearing and echolocation in the earliest toothed whales.

PubMed

Park, Travis; Fitzgerald, Erich M G; Evans, Alistair R

2016-04-01

The evolution of biosonar (production of high-frequency sound and reception of its echo) was a key innovation of toothed whales and dolphins (Odontoceti) that facilitated phylogenetic diversification and rise to ecological predominance. Yet exactly when high-frequency hearing first evolved in odontocete history remains a fundamental question in cetacean biology. Here, we show that archaic odontocetes had a cochlea specialized for sensing high-frequency sound, as exemplified by an Oligocene xenorophid, one of the earliest diverging stem groups. This specialization is not as extreme as that seen in the crown clade. Paired with anatomical correlates for high-frequency signal production in Xenorophidae, this is strong evidence that the most archaic toothed whales possessed a functional biosonar system, and that this signature adaptation of odontocetes was acquired at or soon after their origin. © 2016 The Author(s).

History and contemporary significance of the Rhynie cherts-our earliest preserved terrestrial ecosystem.

PubMed

Edwards, Dianne; Kenrick, Paul; Dolan, Liam

2018-02-05

The Rhynie cherts Unit is a 407 million-year old geological site in Scotland that preserves the most ancient known land plant ecosystem, including associated animals, fungi, algae and bacteria. The quality of preservation is astonishing, and the initial description of several plants 100 years ago had a huge impact on botany. Subsequent discoveries provided unparalleled insights into early life on land. These include the earliest records of plant life cycles and fungal symbioses, the nature of soil microorganisms and the diversity of arthropods. Today the Rhynie chert (here including the Rhynie and Windyfield cherts) takes on new relevance, especially in relation to advances in the fields of developmental genetics and Earth systems science. New methods and analytical techniques also contribute to a better understanding of the environment and its organisms. Key discoveries are reviewed, focusing on the geology of the site, the organisms and the palaeoenvironments. The plants and their symbionts are of particular relevance to understanding the early evolution of the plant life cycle and the origins of fundamental organs and tissue systems. The Rhynie chert provides remarkable insights into the structure and interactions of early terrestrial communities, and it has a significant role to play in developing our understanding of their broader impact on Earth systems.This article is part of a discussion meeting issue 'The Rhynie cherts: our earliest terrestrial ecosystem revisited'. © 2017 The Author(s).

Distribution of HLA-A, -B and -DRB1 alleles in the Kensiu and Semai Orang Asli sub-groups in Peninsular Malaysia.

PubMed

Tasnim, Abd Razak; Allia, Shahril; Edinur, Hisham Atan; Panneerchelvam, Sundararajulu; Zafarina, Zainuddin; Norazmi, Mohd Nor

2016-08-01

The earliest settlers in Peninsular Malaysia are the Orang Asli population, namely Semang, Senoi and Proto Malays. In the present study, we typed the HLA-A, -B and -DRB1 loci of the Kensiu and Semai Orang Asli sub-groups. Sequence-based HLA typing was performed on 59 individuals from two Orang Asli sub-groups. A total of 11, 18 and 14 HLA-A, -B and -DRB1 alleles were identified, respectively. These data are available in the Allele Frequencies Net Database under the population name "Malaysia Kedah Kensiu" and "Malaysia Pahang Semai". Copyright © 2016 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Sovereignty and social justice: how the concepts affect federal American Indian policy and American Indian health.

PubMed

Unal, Donalee

2018-01-01

The health disparities that are prevalent among American Indian and Alaska Native (AI/AN) communities are connected to the ideology of sovereignty and often ignored in social work and public health literature. Therefore, the purpose of this paper is to examine the health outcomes of American Indians from the time of contact with European settlers to the present through the ideology of sovereignty and federal government AI health policy. The foundation for the health outcomes of AIs and the governmental policies affecting them lie in the ideology of tribal sovereignty. This ideology has greatly impacted how the government views and treats AIs and consequently, how it has impacted their health. From the earliest treaties between European settlers and AIs, this legal relationship has been and remains a perplexing issue. With the examination of tribal sovereignty comes the realization that colonization and governmental polices have greatly contributed to the many social and health problems that AIs suffer from today. Understanding that the health disparities that exist among AI/AN populations cannot only be attributed to individual behavior and choice but is driven by societal, economic and political factors may be used to inform social work education, practice, and research.

Buried Impact Basins and the Earliest History of Mars

NASA Technical Reports Server (NTRS)

Frey, H. V.

2003-01-01

The "Quasi-Circular Depressions" (QCDs) seen in MOLA data which have little or no visible appearance in image data have been interpreted as buried impact basins on Mars. These have important implications for the age of the lowland crust, what mechanisms could produce the crustal dichotomy, and the existence of crust older than the oldest observed surface units on Mars. A global survey of large QCDs using high resolution MOLA data now available has provided further details of the earliest history of Mars. The lowlands are of Early Noachian age, slightly younger than the buried highlands and definitely older than the exposed highland surface. A depopulation of large visible basins at diameters 800 to 1300 km suggests some global scale event early in martian history, maybe related to the formation of the lowlands and/or the development of Tharsis. A suggested early disappearance of the global magnetic field can be placed within a temporal sequence of formation of the very largest impact basins.

Boreal earliest Triassic biotas elucidate globally depauperate hard substrate communities after the end-Permian mass extinction.

PubMed

Zatoń, Michał; Niedźwiedzki, Grzegorz; Blom, Henning; Kear, Benjamin P

2016-11-08

The end-Permian mass extinction constituted the most devastating biotic crisis of the Phanerozoic. Its aftermath was characterized by harsh marine conditions incorporating volcanically induced oceanic warming, widespread anoxia and acidification. Bio-productivity accordingly experienced marked fluctuations. In particular, low palaeolatitude hard substrate communities from shallow seas fringing Western Pangaea and the Tethyan Realm were extremely impoverished, being dominated by monogeneric colonies of filter-feeding microconchid tubeworms. Here we present the first equivalent field data for Boreal hard substrate assemblages from the earliest Triassic (Induan) of East Greenland. This region bordered a discrete bio-realm situated at mid-high palaeolatitude (>30°N). Nevertheless, hard substrate biotas were compositionally identical to those from elsewhere, with microconchids encrusting Claraia bivalves and algal buildups on the sea floor. Biostratigraphical correlation further shows that Boreal microconchids underwent progressive tube modification and unique taxic diversification concordant with changing habitats over time. We interpret this as a post-extinction recovery and adaptive radiation sequence that mirrored coeval subequatorial faunas, and thus confirms hard substrate ecosystem depletion as a hallmark of the earliest Triassic interval globally.

Boreal earliest Triassic biotas elucidate globally depauperate hard substrate communities after the end-Permian mass extinction

NASA Astrophysics Data System (ADS)

Zatoń, Michał; Niedźwiedzki, Grzegorz; Blom, Henning; Kear, Benjamin P.

2016-11-01

The end-Permian mass extinction constituted the most devastating biotic crisis of the Phanerozoic. Its aftermath was characterized by harsh marine conditions incorporating volcanically induced oceanic warming, widespread anoxia and acidification. Bio-productivity accordingly experienced marked fluctuations. In particular, low palaeolatitude hard substrate communities from shallow seas fringing Western Pangaea and the Tethyan Realm were extremely impoverished, being dominated by monogeneric colonies of filter-feeding microconchid tubeworms. Here we present the first equivalent field data for Boreal hard substrate assemblages from the earliest Triassic (Induan) of East Greenland. This region bordered a discrete bio-realm situated at mid-high palaeolatitude (>30°N). Nevertheless, hard substrate biotas were compositionally identical to those from elsewhere, with microconchids encrusting Claraia bivalves and algal buildups on the sea floor. Biostratigraphical correlation further shows that Boreal microconchids underwent progressive tube modification and unique taxic diversification concordant with changing habitats over time. We interpret this as a post-extinction recovery and adaptive radiation sequence that mirrored coeval subequatorial faunas, and thus confirms hard substrate ecosystem depletion as a hallmark of the earliest Triassic interval globally.

A structural intermediate between triisodontids and mesonychians (Mammalia, Acreodi) from the earliest Eocene of Portugal.

PubMed

Tabuce, Rodolphe; Clavel, Julien; Antunes, Miguel Telles

2011-02-01

A new mammal, Mondegodon eutrigonus gen. et sp. nov., is described from the earliest Eocene locality of Silveirinha, Portugal. This species shows dental adaptations indicative of a carnivorous diet. M. eutrigonus is referred to the order Acreodi and considered, along with the early Paleocene North American species Oxyclaenus cuspidatus, as a morphological intermediate between two groups of ungulate-like mammals, namely, the triisodontids and mesonychians. Considering that triisodontids are early to early-late Paleocene North American taxa, Mondegodon probably belongs to a group that migrated from North America towards Europe during the first part of the Paleocene. Mondegodon could represent thus a relict genus, belonging to the ante-Eocene European mammalian fauna. The occurrence of such a taxon in Southern Europe may reflect a period of isolation of this continental area during the Paleocene/Eocene transition. In this context, the non-occurrence of closely allied forms of Mondegodon in the Eocene North European mammalian faunas is significant. This strengthens the hypothesis that the mammalian fauna from Southern Europe is characterized by a certain degree of endemism during the earliest Eocene. Mondegodon also presents some striking similarities with an unnamed genus from the early Eocene of India which could represent the first Asian known transitional form between the triisodontids and mesonychians.

Culture effects on adults' earliest childhood recollection and self-description: implications for the relation between memory and the self.

PubMed

Wang, Q

2001-08-01

American and Chinese college students (N = 256) reported their earliest childhood memory on a memory questionnaire and provided self-descriptions on a shortened 20 Statements Test (M. H. Kuhn & T. S. McPartland, 1954). The average age at earliest memory of Americans was almost 6 months earlier than that of Chinese. Americans reported lengthy, specific, self-focused, and emotionally elaborate memories; they also placed emphasis on individual attributes in describing themselves. Chinese provided brief accounts of childhood memories centering on collective activities, general routines, and emotionally neutral events; they also included a great number of social roles in their self-descriptions. Across the entire sample, individuals who described themselves in more self-focused and positive terms provided more specific and self-focused memories. Findings are discussed in light of the interactive relation between autobiographical memory and cultural self-construal.

Fate and Contribution of Internal Wave-Forced Barnacle Settlers to Community Structure in Northern Baja California, a Year after Settlement

NASA Astrophysics Data System (ADS)

Lievana, A.; Ladah, L. B.; Lavin, M. F.; Filonov, A. E.; Tapia, F. J.; Leichter, J.; Valencia Gasti, J. A.

2016-02-01

Physical transport processes, such as nonlinear internal waves, operating within the coastal ocean of Baja California, Mexico, are diverse, variable and operate on a variety of temporal and spatial scales. Understanding the influence of nonlinear internal waves, in part responsible for the exchange of water properties between coastal and offshore environments, on the structure of intertidal communities is important for the generation of working ecological models. The relationship between the supply of ecological subsidies associated with physical transport processes that operate on relatively short spatial and temporal scales, such as the internal tide, and intertidal community structure must be understood as processes that operate on distinct spatial and temporal scales may be prone to react uniquely as the climate changes. We designed an experiment to quantify recruitment and adult survivorship of Chthamalus sp. whose settlement was associated with internal wave activity in the nearby ocean and found that the number of settlers was a robust predictor of the number of adults observed, indicating that post-settlement processes such as competition and predation are not likely to significantly affect the structure of the intertidal barnacle community resulting from internal-wave forced settlement.

Shall we upgrade one-dimensional secondary settler models used in WWTP simulators? - An assessment of model structure uncertainty and its propagation.

PubMed

Plósz, Benedek Gy; De Clercq, Jeriffa; Nopens, Ingmar; Benedetti, Lorenzo; Vanrolleghem, Peter A

2011-01-01

In WWTP models, the accurate assessment of solids inventory in bioreactors equipped with solid-liquid separators, mostly described using one-dimensional (1-D) secondary settling tank (SST) models, is the most fundamental requirement of any calibration procedure. Scientific knowledge on characterising particulate organics in wastewater and on bacteria growth is well-established, whereas 1-D SST models and their impact on biomass concentration predictions are still poorly understood. A rigorous assessment of two 1-DSST models is thus presented: one based on hyperbolic (the widely used Takács-model) and one based on parabolic (the more recently presented Plósz-model) partial differential equations. The former model, using numerical approximation to yield realistic behaviour, is currently the most widely used by wastewater treatment process modellers. The latter is a convection-dispersion model that is solved in a numerically sound way. First, the explicit dispersion in the convection-dispersion model and the numerical dispersion for both SST models are calculated. Second, simulation results of effluent suspended solids concentration (XTSS,Eff), sludge recirculation stream (XTSS,RAS) and sludge blanket height (SBH) are used to demonstrate the distinct behaviour of the models. A thorough scenario analysis is carried out using SST feed flow rate, solids concentration, and overflow rate as degrees of freedom, spanning a broad loading spectrum. A comparison between the measurements and the simulation results demonstrates a considerably improved 1-D model realism using the convection-dispersion model in terms of SBH, XTSS,RAS and XTSS,Eff. Third, to assess the propagation of uncertainty derived from settler model structure to the biokinetic model, the impact of the SST model as sub-model in a plant-wide model on the general model performance is evaluated. A long-term simulation of a bulking event is conducted that spans temperature evolution throughout a summer

Equatorial Precession Drove Mid-Latitude Changes in ENSO-Scale Variation in the Earliest Miocene

NASA Astrophysics Data System (ADS)

Fox, B.; D'Andrea, W. J.; Lee, D. E.; Wilson, G. S.

2014-12-01

Foulden Maar is an annually laminated lacustrine diatomite deposit from the South Island of New Zealand. The deposit was laid down over ~100 kyr of the latest Oligocene and earliest Miocene, during the peak and deglaciation phase of the Mi-1 Antarctic glaciation event. At this time, New Zealand was located at approximately the same latitude as today (~45°S). Evidence from organic geochemical proxies (δD, δ13C) and physical properties (density, colour) indicates the presence of an 11-kyr cycle at the site. Although it is known that 11-kyr insolation (half-precession) cycles occur between the Tropics, this cycle is rarely seen in sedimentary archives deposited outside the immediate vicinity of the Equator. Records from Foulden Maar correlate well with the amplitude and phase of the modelled equatorial half-precession cycle for the earliest Miocene. High-resolution (50 µm) colour intensity measurements and lamina thickness measurements both indicate the presence of significant ENSO-like (2-8 year) variation in the Foulden Maar sediments. Early results from targeted lamina thickness measurements suggest that ENSO-band variation is modulated by the 11-kyr cycle, with power in the ENSO band increasing during periods of increased insolation at the Equator. This implies that equatorial half-precession had a significant effect on ENSO-like variation in the early Miocene, and that this effect was felt as far afield as the mid-latitudes of the Southern Hemisphere.

The first skull of the earliest giant panda

PubMed Central

Jin, Changzhu; Ciochon, Russell L.; Dong, Wei; Hunt, Robert M.; Liu, Jinyi; Jaeger, Marc; Zhu, Qizhi

2007-01-01

Fossils of the giant panda Ailuropoda (Order Carnivora, Family Ursidae) are largely isolated teeth, mandibles, and a few rare skulls, known from the late Pliocene to late Pleistocene in China and Southeast Asia. Much of this material represents a Pleistocene chronospecies, Ailuropoda baconi, an animal larger than the living giant panda, Ailuropoda melanoleuca. The earliest certain record of Ailuropoda is the late Pliocene chronospecies, Ailuropoda microta, smaller than either A. baconi or A. melanoleuca, and previously known only from teeth and a few mandibles from karst caves in south China. Here, we report the discovery of the first skull of A. microta, establishing its cranial anatomy and demonstrating that the specialized cranial and dental adaptations of Ailuropoda for durophagous feeding behavior centered on bamboo were already evident in this late Pliocene species. The skull from Jinyin cave (Guangxi) and dental remains from other karst localities in southeastern China show that Ailuropoda microta occupied south China from ≈2 to 2.4 Myr ago after a marked global climatic deterioration. Dental and basicranial anatomy indicate a less specialized morphology early in the history of the lineage and support derivation of the giant panda from the Miocene Asian ursid Ailurarctos PMID:17578912

The earliest evidence of true lambdoid craniosynostosis: the case of "Benjamina", a Homo heidelbergensis child.

PubMed

Gracia, Ana; Martínez-Lage, Juan F; Arsuaga, Juan-Luis; Martínez, Ignacio; Lorenzo, Carlos; Pérez-Espejo, Miguel-Angel

2010-06-01

The authors report the morphological and neuroimaging findings of an immature human fossil (Cranium 14) diagnosed with left lambdoid synostosis. The skull was recovered at the Sima de los Huesos site in Atapuerca (Burgos, Spain). Since the human fossil remains from this site have been dated to a minimum age of 530,000 years, this skull represents the earliest evidence of craniosynostosis occurring in a hominid. A brief historical review of craniosynostosis and cranial deformation is provided.

Anticipating persistent infection

NASA Astrophysics Data System (ADS)

Moitra, Promit; Jain, Kanishk; Sinha, Sudeshna

2018-03-01

We explore the emergence of persistent infection in a closed region where the disease progression of the individuals is given by the SIRS model, with an individual becoming infected on contact with another infected individual within a given range. We focus on the role of synchronization in the persistence of contagion. Our key result is that higher degree of synchronization, both globally in the population and locally in the neighbourhoods, hinders persistence of infection. Importantly, we find that early short-time asynchrony appears to be a consistent precursor to future persistence of infection, and can potentially provide valuable early warnings for sustained contagion in a population patch. Thus, transient synchronization can help anticipate the long-term persistence of infection. Further we demonstrate that when the range of influence of an infected individual is wider, one obtains lower persistent infection. This counterintuitive observation can also be understood through the relation between synchronization and infection burn-out.

Aurorae: The earliest datable observation of the aurora borealis

NASA Astrophysics Data System (ADS)

Stephenson, F. Richard; Willis, David M.; Hallinan, Thomas J.

2004-12-01

The Late Babylonian astronomical texts, discovered at the site of Babylon (32.5°N, 44.4°E) more than a century ago, contain what is probably the earliest reliable account of the aurora borealis. A clay tablet recording numerous celestial observations made by the official astronomers during the 37th year of King Nebuchadnezzar II (568/567 BC) describes an unusual ``red glow'' in the sky at night; the exact date of this observation corresponds to the night of 12/13 March in 567 BC. The most likely interpretation of the phenomenon is an auroral display. This event occurred several centuries before the first clearly identifiable observation of the aurora from elsewhere in the world, namely China in 193 BC. The Babylonian auroral observation is remarkable in the sense that it is one of a series of carefully recorded astronomical observations, for each of which the year, month and day are known precisely. This observation occurred at a time when the geomagnetic (dipole) latitude of Babylon was about 41°N compared with the present value of 27.5°N, suggesting a higher auroral incidence at Babylon in 567 BC than at present.

Earliest economic exploitation of chicken outside East Asia: Evidence from the Hellenistic Southern Levant

PubMed Central

Perry-Gal, Lee; Erlich, Adi; Gilboa, Ayelet; Bar-Oz, Guy

2015-01-01

Chicken (Gallus gallus domesticus) is today one of the most widespread domesticated species and is a main source of protein in the human diet. However, for thousands of years exploitation of chickens was confined to symbolic and social domains such as cockfighting. The question of when and where chickens were first used for economic purposes remains unresolved. The results of our faunal analysis demonstrate that the Hellenistic (fourth–second centuries B.C.E.) site of Maresha, Israel, is the earliest site known today where economic exploitation of chickens was widely practiced. We base our claim on the exceptionally high frequency of chicken bones at that site, the majority of which belong to adult individuals, and on the observed 2:1 ratio of female to male bones. These results are supported further by an extensive survey of faunal remains from 234 sites in the Southern Levant, spanning more than three millennia, which shows a sharp increase in the frequency of chicken during the Hellenistic period. We further argue that the earliest secure evidence for economic exploitation of chickens in Europe dates to the first century B.C.E. and therefore is predated by the finds in the Southern Levant by at least a century. We suggest that the gradual acclimatization of chickens in the Southern Levant and its gradual integration into the local economy, the latter fully accomplished in the Hellenistic period, was a crucial step in the adoption of this species in European husbandry some 100 y later. PMID:26195775

Sequencing the Earliest Stages of Active Galactic Nuclei Development Using The Youngest Radio Sources

NASA Astrophysics Data System (ADS)

Collier, Jordan; Filipovic, Miroslav; Norris, Ray; Chow, Kate; Huynh, Minh; Banfield, Julie; Tothill, Nick; Sirothia, Sandeep Kumar; Shabala, Stanislav

2014-04-01

This proposal is a continuation of an extensive project (the core of Collier's PhD) to explore the earliest stages of AGN formation, using Gigahertz-Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) sources. Both are widely believed to represent the earliest stages of radio-loud AGN evolution, with GPS sources preceding CSS sources. In this project, we plan to (a) test this hypothesis, (b) place GPS and CSS sources into an evolutionary sequence with a number of other young AGN candidates, and (c) search for evidence of the evolving accretion mode. We will do this using high-resolution radio observations, with a number of other multiwavelength age indicators, of a carefully selected complete faint sample of 80 GPS/CSS sources. Analysis of the C2730 ELAIS-S1 data shows that we have so far met our goals, resolving the jets of 10/49 sources, and measuring accurate spectral indices from 0.843-10 GHz. This particular proposal is to almost triple the sample size by observing an additional 80 GPS/CSS sources in the Chandra Deep Field South (arguably the best-studied field) and allow a turnover frequency - linear size relation to be derived at >10-sigma. Sources found to be unresolved in our final sample will subsequently be observed with VLBI. Comparing those sources resolved with ATCA to the more compact sources resolved with VLBI will give a distribution of source sizes, helping to answer the question of whether all GPS/CSS sources grow to larger sizes.

Spatial summation revealed in the earliest visual evoked component C1 and the effect of attention on its linearity.

PubMed

Chen, Juan; Yu, Qing; Zhu, Ziyun; Peng, Yujia; Fang, Fang

2016-01-01

In natural scenes, multiple objects are usually presented simultaneously. How do specific areas of the brain respond to multiple objects based on their responses to each individual object? Previous functional magnetic resonance imaging (fMRI) studies have shown that the activity induced by a multiobject stimulus in the primary visual cortex (V1) can be predicted by the linear or nonlinear sum of the activities induced by its component objects. However, there has been little evidence from electroencephelogram (EEG) studies so far. Here we explored how V1 responded to multiple objects by comparing the EEG signals evoked by a three-grating stimulus with those evoked by its two components (the central grating and 2 flanking gratings). We focused on the earliest visual component C1 (onset latency of ∼50 ms) because it has been shown to reflect the feedforward responses of neurons in V1. We found that when the stimulus was unattended, the amplitude of the C1 evoked by the three-grating stimulus roughly equaled the sum of the amplitudes of the C1s evoked by its two components, regardless of the distances between these gratings. When the stimulus was attended, this linear spatial summation existed only when the three gratings were far apart from each other. When the three gratings were close to each other, the spatial summation became compressed. These results suggest that the earliest visual responses in V1 follow a linear summation rule when attention is not involved and that attention can affect the earliest interactions between multiple objects. Copyright © 2016 the American Physiological Society.

Persistent Organic Pollutants in Biotic and Abiotic Components of Antarctic Pristine Environment

NASA Astrophysics Data System (ADS)

Bhardwaj, Laxmikant; Chauhan, Abhishek; Ranjan, Anuj; Jindal, Tanu

2018-02-01

Over the past decades, research in Antarctica has built a new understanding of Antarctica, its past, present and future. Human activities and long-range pollutants are increasing on the Antarctic continent. Research on persistent organic pollutants (POPs) has been carried out internationally by several countries having their permanent research stations to explain the impact of an ever increasing range of POPs in Antarctic ecosystem. POPs have been detected in Antarctica despite its geographical isolation and almost complete absence of human settlements. The presence of POPs in different abiotic (atmosphere, water bodies, sediments, soil, sea ice) and biotic components (mosses, lichens, krill, penguins, skua, etc.) in Antarctica has been studied and documented around for decades and has either been banned or strictly regulated but is still found in the environment. This review focuses on recent research pertaining to sources and occurrence of POPs in Antarctic lake water, soil, sediment, lichen, mosses and other Antarctic marine community. This review also proposes to summarize the current state of research on POPs in Antarctica environment and draw the earliest conclusions on possible significance of POPs in Antarctica based on presently available information from related Antarctic environment.

Persistent Organic Pollutants in Biotic and Abiotic Components of Antarctic Pristine Environment

NASA Astrophysics Data System (ADS)

Bhardwaj, Laxmikant; Chauhan, Abhishek; Ranjan, Anuj; Jindal, Tanu

2018-05-01

Over the past decades, research in Antarctica has built a new understanding of Antarctica, its past, present and future. Human activities and long-range pollutants are increasing on the Antarctic continent. Research on persistent organic pollutants (POPs) has been carried out internationally by several countries having their permanent research stations to explain the impact of an ever increasing range of POPs in Antarctic ecosystem. POPs have been detected in Antarctica despite its geographical isolation and almost complete absence of human settlements. The presence of POPs in different abiotic (atmosphere, water bodies, sediments, soil, sea ice) and biotic components (mosses, lichens, krill, penguins, skua, etc.) in Antarctica has been studied and documented around for decades and has either been banned or strictly regulated but is still found in the environment. This review focuses on recent research pertaining to sources and occurrence of POPs in Antarctic lake water, soil, sediment, lichen, mosses and other Antarctic marine community. This review also proposes to summarize the current state of research on POPs in Antarctica environment and draw the earliest conclusions on possible significance of POPs in Antarctica based on presently available information from related Antarctic environment.

Technique: imaging earliest tooth development in 3D using a silver-based tissue contrast agent.

PubMed

Raj, Muhammad T; Prusinkiewicz, Martin; Cooper, David M L; George, Belev; Webb, M Adam; Boughner, Julia C

2014-02-01

Looking in microscopic detail at the 3D organization of initiating teeth within the embryonic jaw has long-proved technologically challenging because of the radio-translucency of these tiny un-mineralized oral tissues. Yet 3D image data showing changes in the physical relationships among developing tooth and jaw tissues are vital to understand the coordinated morphogenesis of vertebrate teeth and jaws as an animal grows and as species evolve. Here, we present a new synchrotron-based scanning solution to image odontogenesis in 3D and in histological detail using a silver-based contrast agent. We stained fixed, intact wild-type mice aged embryonic (E) day 10 to birth with 1% Protargol-S at 37°C for 12-32 hr. Specimens were scanned at 4-10 µm pixel size at 28 keV, just above the silver K-edge, using micro-computed tomography (µCT) at the Canadian Light Source synchrotron. Synchrotron µCT scans of silver-stained embryos showed even the earliest visible stages of tooth initiation, as well as many other tissue types and structures, in histological detail. Silver stain penetration was optimal for imaging structures in intact embryos E15 and younger. This silver stain method offers a powerful yet straightforward approach to visualize at high-resolution and in 3D the earliest stages of odontogenesis in situ, and demonstrates the important of studying the tooth organ in all three planes of view. Copyright © 2013 Wiley Periodicals, Inc.

The anti-adherence effect of Piper betle and Psidium guajava extracts on the adhesion of early settlers in dental plaque to saliva-coated glass surfaces.

PubMed

Razak, Fathilah Abdul; Rahim, Zubaidah Haji Abd

2003-12-01

The aqueous extracts of Piper betle and Psidium guajava were prepared and tested for their anti-adherence effect on the adhesion of early plaque settlers (Strep. mitis, Strep. sanguinis and Actinomyces sp.). The saliva-coated glass surfaces were used to simulate the pellicle-coated enamel surface in the oral cavity. Our results showed that the anti-adherence activities of Piper betle and Psidium guajava extracts towards the bacteria were different between the bacterial species. Psidium guajava was shown to have a slightly greater anti-adherence effect on Strep. sanguinis by 5.5% and Actinomyces sp. by 10% and a significantly higher effect on Strep. mitis (70%) compared to Piper betle. The three bacterial species are known to be highly hydrophobic, and that hydrophobic bonding seemed to be an important factor in their adherence activities. It is therefore suggested that the plant extracts, in expressing their anti-adherence activities, could have altered the hydrophobic nature of the bonding between the bacteria and the saliva-coated glass surfaces.

Earliest known unequivocal rhinocerotoid sheds new light on the origin of Giant Rhinos and phylogeny of early rhinocerotoids.

PubMed

Wang, Haibing; Bai, Bin; Meng, Jin; Wang, Yuanqing

2016-12-21

Forstercooperiines are a group of primitive rhinocerotoids with a relatively large body size in the Eocene, and normally considered to be closely related to Giant Rhinos. Here we report a new forstercooperiine, Pappaceras meiomenus sp. nov., from the late Early Eocene Arshanto Formation, Erlian Basin, Nei Mongol, China. Pappaceras is the earliest known unequivocal rhinocerotoid, and the holotype of the new species, represented by the most complete cranium of forstercooperiines known to date, shows the earliest evidence of reduction of the first upper premolar in rhinocerotoids, and resembles paraceratheriine Juxia in basicranial features, supporting the interpretation that the forstercooperiine clade is ancestral to paraceratheriines. The new species also displays some similarities with amynodontids in craniodental structures. Phylogenetic analysis identifies P. meiomenus as a basal taxon of the monophyletic forstercooperiines. It also reveals novel phylogenetic relationships of early rhinocerotoids that indicates Uintaceras is the sister group of paraceratheriids, to which amynodontids are more closely related than to any other group of rhinocerotoids. Furthermore, the eggysodontid clade is excluded from hyracodontids and placed as the sister group of rhinocerotids. Hyracodontidae, excluding paraceratheriids and eggysodontids, is placed as the most basal group of the rhinocerotoids.

Sangkulirang Mangkalihat: The Earliest Prehistoric Rock-Art in the World

NASA Astrophysics Data System (ADS)

Imam Gozali Sumantri, Dirga; Soeria Atmadja, Dicky A. S.; Setiawan, Pindi

2018-05-01

Borneo island, a part of Sundaland - a great mainland in South East Asia thousands of years ago - is the largest island in Indonesian Archipelago. In the middle-eastern of East Borneo, lies a peninsula karst region named Sangkulirang Mangkalihat. The region's biodiversity contains many species of flora and fauna which are part of karst ecosystem. Surprisingly, thousands prehistoric rock art paintings and engraving were found here, spread over 48 inland caves in seven different karst mountain areas. The rock arts are painted on the ceiling, wall, and hollow of the cave depends on the meaning. They illustrate forms such as spiritual images (zoomorphic and antropomorphic) for sacred spiritual meaning, and social phenomenon images (tools and weapons) for description of daily life. From all those rock-arts, hand paintings are the most common elements appeared. Compared to other paintings, these are the only negative images using different techniques. Radiocarbon dating indicated that the rock-arts at Tewet Cave in Sangkulirang Mangkalihat is 40,000 BP. It is much earlier compared to Lascaux Cave (35,400 BP) and Chauvet Cave (32,000) in France which were previously known as the earliest one in the world. Rock arts and some archeological findings also indicate the migration of Austronesian People. During the migration, Borneo's climate and land cover were changing from time to time. Continental climate occurred when all Sundaland was still dry (40,000-21,000 BP), followed by tropical savanna climate and archipelagic climate (12,000-7.000 BP), and then Tropical Rainforest consecutively (1,000 BP). Correlatively, geological interpretations from such areas indicate land cover changes. These changes effected Austronesian ways of living, e.g. from hunting to fishing, and were depicted clearly on their paintings. Today, - as observed from time series satellite images - industrial activities such as karst exploitation for cement production and

Microbial biosynthesis of wax esters during desiccation: an adaptation for colonization of the earliest terrestrial environments?

NASA Astrophysics Data System (ADS)

Finkelstein, D. B.; Brassell, S. C.; Pratt, L. M.

2008-12-01

Biosynthesis of wax esters (WE) by prokaryotes in natural systems, notably bacteria from hot springs and marine phytoplankton, is poorly documented, primarily because saponification is a routine step in the analysis of microbial mat lipids. Use of this preparative procedure, critical for characterization of the diagnostic distributions of carboxylic acids in phospholipids, precludes recovery of intact WE. Examination of non-saponified lipids in emergent and desiccated mats with comparable microbial communities from the Warner Lake region, Oregon, reveals increases in the relative abundance (18.6 to 59.9μg/g Corg) and average chain length (C38 to C46) of WE in the latter, combined with assimilation of phytol and tocopherol moieties. Prokaryotes can accumulate WE as storage lipids in vitro, notably at elevated temperature or under nitrogen limiting conditions, but we propose that biosynthesis of long-chain WE that have a low solubility and are resistant to degradation/oxidation may represent an evolutionary strategy to survive desiccation in evaporative environments. Moreover, aeolian transport of desiccated mat-rip-ups between lake flats allows for migration of microbial communities within and between lake flats and basins during arid conditions. Subsequent rehydration within an alkaline environment would naturally saponify WE, and thereby regenerate alcohol and acid moieties that could serve as membrane lipids for the next viable microbial generation. The evolutionary cradle of WE was likely abiotic generation under hydrothermal conditions, which is consistent with the antiquity of the ester linkage necessitated by its integral role in the membranes of Eubacteria (though not Archaea) and in bacteriochlorophyll. The subsequent capability of microbes to biosynthesize WE may have facilitated their survival when nutrients were limiting, and production of long-chain WE (>C40) may represent a further critical evolutionary threshold that enabled their persistence through

Micropredation on sea urchins as a potential stabilizing process for rocky reefs

NASA Astrophysics Data System (ADS)

Bonaviri, Chiara; Gianguzza, Paola; Pipitone, Carlo; Hereu, Bernat

2012-10-01

Rocky reefs can shift from forest, a state dominated by erect algae with high biodiversity, to barren, an impoverished state dominated by encrusting algae. Sea urchins, abundant in barrens, are usually held responsible for the maintenance of this state. Predation by large fish can revert the barren state to forest by controlling sea urchin populations. However, the persistence of a community state sometimes seems to be independent from the presence of such large predators, suggesting the existence of other unknown mechanisms ensuring their stability. Theoretical studies suggest that the settler stage of sea urchins is determinant for maintaining a given rocky reef state. In this study, we have identified several potential invertebrate micropredators of settlers of the sea urchin Paracentrotus lividus and measured their predation activity. Predation rates showed marked differences among species, possibly due to morphological and/or behavioral traits. Micropredators were more abundant in the forest than in barren, and their potential impact on the sea urchin community differed between the two states by two orders of magnitude. These findings suggest a novel self-perpetuating mechanism stabilizing rocky reef systems, where the abundance of micropredators may contribute to shape the sea urchin population, which in turn is responsible for the persistence of the state.

Volutidae (Mollusca: Gastropoda) of the Lakhra Formation (Earliest Eocene, Sindh, Pakistan): systematics, biostratigraphy and paleobiogeography.

PubMed

Merle, Didier; Pacaud, Jean-Michel; Métais, Grégoire; Bartolini, Annachiara; Lashari, Rafiq A; Brohi, Imdad A; Solangi, Sarfraz H; Marivaux, Laurent; Welcomme, Jean-Loup

2014-06-27

The paleobiodiversity of the Volutidae (Mollusca: Gastropoda) of the Ranikot Group (Sindh, Pakistan) and particularly of the Lakhra Formation (SBZ 5 biozone, Earliest Eocene), is reconsidered on the basis of new material collected during recent field trips. Ten new species are described (Mitreola brohii sp. nov., Lyrischapa vredenburgi sp. nov., L. brevispira sp. nov., Athleta (Volutopupa) citharopsis sp. nov., A. (Volutocorbis) lasharii sp. nov., Volutilithes welcommei sp. nov., V. sindhiensis sp. nov., Pseudaulicina coxi sp. nov., Sindhiluta lakhraensis sp. nov. and Pakiluta solangii sp. nov.) and one species is in open nomenclature (Lyria sp.). Three new genera are described: Lyriopsis gen. nov. [Volutinae, ?Lyriini, type species: Lyriopsis cossmanni (Vredenburg, 1923)], Sindhiluta gen. nov. [Volutilithinae, type species: Sindhiluta lakhraensis n. sp.] and Pakiluta gen. nov. [?Volutodermatinae, type species: Pakiluta solangii n. sp.]. Two new combinations are proposed: Lyriopsis cossmanni (Vredenburg, 1923) comb. nov. and Athleta (Volutopupa) intercrenatus (Cossmann & Pissarro, 1909) comb. nov. Lectotypes are designated for Lyria cossmanni Vredenburg, 1923, L. feddeni Vredenburg, 1923, Volutospina noetlingi Cossmann & Pissarro, 1909, V. intercrenata Cossmann & Pissarro, 1909 and Athleta (Volutocorbis) victoriae Vredenburg, 1923. With 21 species, this volutid fauna is the most diverse recorded from the Tethys Ocean during Earliest Eocene time. The assemblage is characterized by a strong turnover marked by regional speciation and the appearance of many western Tethyan invaders. Although at the species level, the assemblage documents a strong provincialism, at the genus level, the high number of shared genera between Eastern Tethyan and Old World Tethyan realms begins a phase of long-term homogeneity of volutid assemblages from the Tethyan paleobiogeographic province.

High-resolution carbon isotope changes in the Permian-Triassic boundary interval, Chongqing, South China; implications for control and growth of earliest Triassic microbialites

NASA Astrophysics Data System (ADS)

Mu, Xinan; Kershaw, Steve; Li, Yue; Guo, Li; Qi, Yuping; Reynolds, Alan

2009-11-01

High-resolution δ 13C CARB analysis of the Permian-Triassic boundary (PTB) interval at the Laolongdong section, Beibei, near the city of Chongqing, south China, encompasses the latest Permian and earliest Triassic major facies changes in the South China Block (SCB). Microbialites form a distinctive unit in the lowermost 190 cm above the top of the Changhsing Formation (latest Permian) at Laolongdong, comparable to a range of earliest Triassic sites in low latitudes in the Tethyan area. The data show that declining values of δ 13C CARB, well-known globally, began at the base of the microbialite. High positive values (+3 to 4 ppt) of δ 13C CARB in the Late Permian are interpreted to indicate storage of 12C in the deep waters of a stratified ocean, that was released during ocean overturn in the earliest Triassic, contributing to the distinctive fall in isotope values; this interpretation has been stated by other authors and is followed here. The δ 13C CARB curve shows fluctuations within the microbialite unit, which are not reflected in the microbialite structure. Comparisons between microbialite branches and adjacent micritic sediment show little difference in δ 13C CARB, demonstrating that the microbialite grew in equilibrium with surrounding seawater. The Early Triassic microbialites are interpreted to be a response to upwelling of bicarbonate-rich poorly oxygenated water in low latitudes of Tethys Ocean, consistent with current ocean models for the PTB interval. However, the decline of δ 13C CARB may be due to a combination of processes, including productivity collapse resulting from mass extinction, return of deep water to ocean surface, oxidation of methane released from methane hydrate destabilisation, and atmospheric deterioration. Nevertheless, build-up of bicarbonate-rich anoxic deep waters may be expected as a result of the partial isolation of Tethys, due to continental geography; release of bicarbonate-rich deep water, by ocean upwelling, in the

Numeric invariants from multidimensional persistence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skryzalin, Jacek; Carlsson, Gunnar

2017-05-19

In this paper, we analyze the space of multidimensional persistence modules from the perspectives of algebraic geometry. We first build a moduli space of a certain subclass of easily analyzed multidimensional persistence modules, which we construct specifically to capture much of the information which can be gained by using multidimensional persistence over one-dimensional persistence. We argue that the global sections of this space provide interesting numeric invariants when evaluated against our subclass of multidimensional persistence modules. Lastly, we extend these global sections to the space of all multidimensional persistence modules and discuss how the resulting numeric invariants might be usedmore » to study data.« less

Fixational Eye Movements in the Earliest Stage of Metazoan Evolution

PubMed Central

Bielecki, Jan; Høeg, Jens T.; Garm, Anders

2013-01-01

All known photoreceptor cells adapt to constant light stimuli, fading the retinal image when exposed to an immobile visual scene. Counter strategies are therefore necessary to prevent blindness, and in mammals this is accomplished by fixational eye movements. Cubomedusae occupy a key position for understanding the evolution of complex visual systems and their eyes are assumedly subject to the same adaptive problems as the vertebrate eye, but lack motor control of their visual system. The morphology of the visual system of cubomedusae ensures a constant orientation of the eyes and a clear division of the visual field, but thereby also a constant retinal image when exposed to stationary visual scenes. Here we show that bell contractions used for swimming in the medusae refresh the retinal image in the upper lens eye of Tripedalia cystophora. This strongly suggests that strategies comparable to fixational eye movements have evolved at the earliest metazoan stage to compensate for the intrinsic property of the photoreceptors. Since the timing and amplitude of the rhopalial movements concur with the spatial and temporal resolution of the eye it circumvents the need for post processing in the central nervous system to remove image blur. PMID:23776673

Fixational eye movements in the earliest stage of metazoan evolution.

PubMed

Bielecki, Jan; Høeg, Jens T; Garm, Anders

2013-01-01

All known photoreceptor cells adapt to constant light stimuli, fading the retinal image when exposed to an immobile visual scene. Counter strategies are therefore necessary to prevent blindness, and in mammals this is accomplished by fixational eye movements. Cubomedusae occupy a key position for understanding the evolution of complex visual systems and their eyes are assumedly subject to the same adaptive problems as the vertebrate eye, but lack motor control of their visual system. The morphology of the visual system of cubomedusae ensures a constant orientation of the eyes and a clear division of the visual field, but thereby also a constant retinal image when exposed to stationary visual scenes. Here we show that bell contractions used for swimming in the medusae refresh the retinal image in the upper lens eye of Tripedalia cystophora. This strongly suggests that strategies comparable to fixational eye movements have evolved at the earliest metazoan stage to compensate for the intrinsic property of the photoreceptors. Since the timing and amplitude of the rhopalial movements concur with the spatial and temporal resolution of the eye it circumvents the need for post processing in the central nervous system to remove image blur.

Bacterial persistence by RNA endonucleases

PubMed Central

Maisonneuve, Etienne; Shakespeare, Lana J.; Jørgensen, Mikkel Girke; Gerdes, Kenn

2011-01-01

Bacteria form persisters, individual cells that are highly tolerant to different types of antibiotics. Persister cells are genetically identical to nontolerant kin but have entered a dormant state in which they are recalcitrant to the killing activity of the antibiotics. The molecular mechanisms underlying bacterial persistence are unknown. Here, we show that the ubiquitous Lon (Long Form Filament) protease and mRNA endonucleases (mRNases) encoded by toxin-antitoxin (TA) loci are required for persistence in Escherichia coli. Successive deletion of the 10 mRNase-encoding TA loci of E. coli progressively reduced the level of persisters, showing that persistence is a phenotype common to TA loci. In all cases tested, the antitoxins, which control the activities of the mRNases, are Lon substrates. Consistently, cells lacking lon generated a highly reduced level of persisters. Moreover, Lon overproduction dramatically increased the levels of persisters in wild-type cells but not in cells lacking the 10 mRNases. These results support a simple model according to which mRNases encoded by TA loci are activated in a small fraction of growing cells by Lon-mediated degradation of the antitoxins. Activation of the mRNases, in turn, inhibits global cellular translation, and thereby induces dormancy and persistence. Many pathogenic bacteria known to enter dormant states have a plethora of TA genes. Therefore, in the future, the discoveries described here may lead to a mechanistic understanding of the persistence phenomenon in pathogenic bacteria. PMID:21788497

Object-oriented Persistent Homology

PubMed Central

Wang, Bao; Wei, Guo-Wei

2015-01-01

Persistent homology provides a new approach for the topological simplification of big data via measuring the life time of intrinsic topological features in a filtration process and has found its success in scientific and engineering applications. However, such a success is essentially limited to qualitative data classification and analysis. Indeed, persistent homology has rarely been employed for quantitative modeling and prediction. Additionally, the present persistent homology is a passive tool, rather than a proactive technique, for classification and analysis. In this work, we outline a general protocol to construct object-oriented persistent homology methods. By means of differential geometry theory of surfaces, we construct an objective functional, namely, a surface free energy defined on the data of interest. The minimization of the objective functional leads to a Laplace-Beltrami operator which generates a multiscale representation of the initial data and offers an objective oriented filtration process. The resulting differential geometry based object-oriented persistent homology is able to preserve desirable geometric features in the evolutionary filtration and enhances the corresponding topological persistence. The cubical complex based homology algorithm is employed in the present work to be compatible with the Cartesian representation of the Laplace-Beltrami flow. The proposed Laplace-Beltrami flow based persistent homology method is extensively validated. The consistence between Laplace-Beltrami flow based filtration and Euclidean distance based filtration is confirmed on the Vietoris-Rips complex for a large amount of numerical tests. The convergence and reliability of the present Laplace-Beltrami flow based cubical complex filtration approach are analyzed over various spatial and temporal mesh sizes. The Laplace-Beltrami flow based persistent homology approach is utilized to study the intrinsic topology of proteins and fullerene molecules. Based on a

Computer Modeling of the Earliest Cellular Structures and Functions

NASA Technical Reports Server (NTRS)

Pohorille, Andrew; Chipot, Christophe; Schweighofer, Karl

2000-01-01

In the absence of extinct or extant record of protocells (the earliest ancestors of contemporary cells). the most direct way to test our understanding of the origin of cellular life is to construct laboratory models of protocells. Such efforts are currently underway in the NASA Astrobiology Program. They are accompanied by computational studies aimed at explaining self-organization of simple molecules into ordered structures and developing designs for molecules that perform proto-cellular functions. Many of these functions, such as import of nutrients, capture and storage of energy. and response to changes in the environment are carried out by proteins bound to membrane< We will discuss a series of large-scale, molecular-level computer simulations which demonstrate (a) how small proteins (peptides) organize themselves into ordered structures at water-membrane interfaces and insert into membranes, (b) how these peptides aggregate to form membrane-spanning structures (eg. channels), and (c) by what mechanisms such aggregates perform essential proto-cellular functions, such as proton transport of protons across cell walls, a key step in cellular bioenergetics. The simulations were performed using the molecular dynamics method, in which Newton's equations of motion for each item in the system are solved iteratively. The problems of interest required simulations on multi-nanosecond time scales, which corresponded to 10(exp 6)-10(exp 8) time steps.

The earliest ossicone and post-cranial record of Giraffa

PubMed Central

Danowitz, Melinda; Barry, John C.

2017-01-01

The oldest Giraffa material presently known consists of dental specimens. The oldest post-cranial Giraffa material belongs to the Plio-Pleistocene taxon Giraffa sivalensis, where the holotype is a third cervical vertebra. We describe three non-dental specimens from the Early Late Miocene of the Potwar Plateau, including an 8.1 million year old ossicone, 9.4 million year old astragalus, and 8.9 million year old metatarsal and refer them to Giraffa. The described ossicone exhibits remarkable similarities with the ossicones of a juvenile modern giraffe, including the distribution of secondary bone growth, posterior curvature, and concave pitted undersurface where the ossicone would attach to the skull. The astragalus has a notably flat grove of the trochlea, medial twisting between the trochlea and the head, and a square-shaped sustentacular facet, all of which characterize the astragalus of Giraffa camelopardalis. The newly described astragalus is narrow and rectangular, unlike the boxy shaped bone of the modern giraffe. The metatarsal is large in size and has a shallow central trough created by thin medial and lateral ridges, a feature unique to Giraffa and Sivatherium. Our described material introduce the earliest non-dental material of Giraffa, a genus whose extinct representation is otherwise dominated by teeth, and demonstrate that the genus has been morphologically consistent over 9 million years. PMID:28926638

The earliest ossicone and post-cranial record of Giraffa.

PubMed

Danowitz, Melinda; Barry, John C; Solounias, Nikos

2017-01-01

The oldest Giraffa material presently known consists of dental specimens. The oldest post-cranial Giraffa material belongs to the Plio-Pleistocene taxon Giraffa sivalensis, where the holotype is a third cervical vertebra. We describe three non-dental specimens from the Early Late Miocene of the Potwar Plateau, including an 8.1 million year old ossicone, 9.4 million year old astragalus, and 8.9 million year old metatarsal and refer them to Giraffa. The described ossicone exhibits remarkable similarities with the ossicones of a juvenile modern giraffe, including the distribution of secondary bone growth, posterior curvature, and concave pitted undersurface where the ossicone would attach to the skull. The astragalus has a notably flat grove of the trochlea, medial twisting between the trochlea and the head, and a square-shaped sustentacular facet, all of which characterize the astragalus of Giraffa camelopardalis. The newly described astragalus is narrow and rectangular, unlike the boxy shaped bone of the modern giraffe. The metatarsal is large in size and has a shallow central trough created by thin medial and lateral ridges, a feature unique to Giraffa and Sivatherium. Our described material introduce the earliest non-dental material of Giraffa, a genus whose extinct representation is otherwise dominated by teeth, and demonstrate that the genus has been morphologically consistent over 9 million years.

Genomic evidence for plant-parasitic nematodes as the earliest Wolbachia hosts

PubMed Central

Brown, Amanda M. V.; Wasala, Sulochana K.; Howe, Dana K.; Peetz, Amy B.; Zasada, Inga A.; Denver, Dee R.

2016-01-01

Wolbachia, one of the most widespread endosymbionts, is a target for biological control of mosquito-borne diseases (malaria and dengue virus), and antibiotic elimination of infectious filarial nematodes. We sequenced and analyzed the genome of a new Wolbachia strain (wPpe) in the plant-parasitic nematode Pratylenchus penetrans. Phylogenomic analyses placed wPpe as the earliest diverging Wolbachia, suggesting two evolutionary invasions into nematodes. The next branches comprised strains in sap-feeding insects, suggesting Wolbachia may have first evolved as a nutritional mutualist. Genome size, protein content, %GC, and repetitive DNA allied wPpe with mutualistic Wolbachia, whereas gene repertoire analyses placed it between parasite (A, B) and mutualist (C, D, F) groups. Conservation of iron metabolism genes across Wolbachia suggests iron homeostasis as a potential factor in its success. This study enhances our understanding of this globally pandemic endosymbiont, highlighting genetic patterns associated with host changes. Combined with future work on this strain, these genomic data could help provide potential new targets for plant-parasitic nematode control. PMID:27734894

Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q.; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

2016-01-01

Phytoliths and biomolecular components extracted from ancient plant remains from Chang’an (Xi’an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang’an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE.

Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau.

PubMed

Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

2016-01-07

Phytoliths and biomolecular components extracted from ancient plant remains from Chang'an (Xi'an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang'an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE.

Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau

PubMed Central

Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q.; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

2016-01-01

Phytoliths and biomolecular components extracted from ancient plant remains from Chang’an (Xi’an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang’an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE. PMID:26738699

Parsing apart the persisters: Etiological mechanisms and criminal offense patterns of moderate- and high-level persistent offenders.

PubMed

Amemiya, Jamie; Vanderhei, Susan; Monahan, Kathryn C

2017-08-01

Longitudinal investigations that have applied Moffitt's dual taxonomic framework to criminal offending have provided support for the existence of adolescent-limited and life-course persistent antisocial individuals, but have also identified additional trajectories. For instance, rather than a single persistent trajectory, studies have found both high-level and moderate-level persistent offenders. To inform theory and progress our understanding of chronic antisocial behavior, the present study used a sample of serious adolescent offenders (N =1,088) followed from middle adolescence to early adulthood (14-25 years), and examined how moderate-level persistent offenders differed from low-rate, desisting, and high-level persistent offenders. Results indicated that moderate-level persisters' etiology and criminal offense patterns were most similar to high-level persisters, but there were notable differences. Specifically, increasing levels of contextual adversity characterized both moderate-level and high-level persisting trajectories, but moderate-level persisters reported consistently lower levels of environmental risk. While both high- and moderate-level persisters committed more drug-related offenses in early adulthood compared to adolescence, moderate-level persisters engaged in lower levels of antisocial behavior across all types of criminal offenses. Taken cumulatively, the findings of this study suggest that sociocontextual interventions may be powerful in reducing both moderate- and high-level persistence in crime.

Genotypic analysis of the earliest known prehistoric case of tuberculosis in Britain.

PubMed

Taylor, G Michael; Young, Douglas B; Mays, Simon A

2005-05-01

The earliest known case of human tuberculosis in Britain dates to the middle period of the Iron Age, approximately 2,200 years before present. Bone lesions on the spine of a male skeleton excavated at Tarrant Hinton in Dorset, United Kingdom, show evidence of Pott's disease and are supported by molecular evidence of Mycobacterium tuberculosis complex DNA amplified by IS6110 PCR (19). In the present study, we used a further series of sensitive PCR methods to confirm the diagnosis of tuberculosis and to determine the genotype of the infecting strain. These tests demonstrated that this individual was infected with a strain of M. tuberculosis rather than Mycobacterium bovis. The strain had undergone the tuberculosis D1 deletion affecting the mmpS6 and mmpL6 genes and can therefore be identified as a member of the family of "modern" M. tuberculosis isolates. All evidence obtained was consistent with surviving mycobacterial DNA being highly fragmented in this case.

The earliest document regarding the history of cranioplasty from the Ottoman era.

PubMed

Aciduman, Ahmet; Belen, Deniz

2007-09-01

Cranioplasty is one of the significant neurosurgical procedures in which the technical advances and also, by some means, drawbacks are still continuing. According to archeological findings and anthropological studies, the earliest procedures regarding cranioplasty date back to just about the same period claimed for trepanation. Ancient surgeons from different geographical sites and cultures performed both practices with remarkable survival rates. However, despite the length of the thriving past of cranioplasty, the first known written record on the topic dates back to late 16th century Europe. Further study of the Ottoman era documents revealed an intriguing text that was written about the repair of skull defects and that dates from early 16th century. This worthy discovery will add valuable contribution to the history of neurosurgery by drawing the written history of cranioplasty more than 60 years back and the use of organic grafts 160 years back. In the present study, this original text is discussed.

The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis

PubMed Central

Li, Yu; Zhang, Bin; Cheng, Huansheng; Zheng, Jianming

2015-01-01

In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070–c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subsequent kiln sites in the vicinity. Using principal components analysis on the major chemical compositions, we reveal the relationships between impressed stoneware and proto-porcelain samples from the six kiln sites. The sherds from different sites have distinctive chemical profiles. The results indicate that the raw materials were procured locally. We find a developmental tendency for early glazes towards mature calcium-based glaze. It is most likely that woody plant ashes with increased calcia-potash ratios were applied to the formula. PMID:26535583

The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis.

PubMed

Li, Yu; Zhang, Bin; Cheng, Huansheng; Zheng, Jianming

2015-01-01

In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070-c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subsequent kiln sites in the vicinity. Using principal components analysis on the major chemical compositions, we reveal the relationships between impressed stoneware and proto-porcelain samples from the six kiln sites. The sherds from different sites have distinctive chemical profiles. The results indicate that the raw materials were procured locally. We find a developmental tendency for early glazes towards mature calcium-based glaze. It is most likely that woody plant ashes with increased calcia-potash ratios were applied to the formula.

Perceptual learning increases the strength of the earliest signals in visual cortex.

PubMed

Bao, Min; Yang, Lin; Rios, Cristina; He, Bin; Engel, Stephen A

2010-11-10

Training improves performance on most visual tasks. Such perceptual learning can modify how information is read out from, and represented in, later visual areas, but effects on early visual cortex are controversial. In particular, it remains unknown whether learning can reshape neural response properties in early visual areas independent from feedback arising in later cortical areas. Here, we tested whether learning can modify feedforward signals in early visual cortex as measured by the human electroencephalogram. Fourteen subjects were trained for >24 d to detect a diagonal grating pattern in one quadrant of the visual field. Training improved performance, reducing the contrast needed for reliable detection, and also reliably increased the amplitude of the earliest component of the visual evoked potential, the C1. Control orientations and locations showed smaller effects of training. Because the C1 arises rapidly and has a source in early visual cortex, our results suggest that learning can increase early visual area response through local receptive field changes without feedback from later areas.

Persistence of West Nile virus.

PubMed

Garcia, Melissa N; Hasbun, Rodrigo; Murray, Kristy O

2015-02-01

West Nile virus (WNV) is a widespread global pathogen that results in significant morbidity and mortality. Data from animal models provide evidence of persistent renal and neurological infection from WNV; however, the possibility of persistent infection in humans and long-term neurological and renal outcomes related to viral persistence remain largely unknown. In this paper, we provide a review of the literature related to persistent infection in parallel with the findings from cohorts of patients with a history of WNV infection. The next steps for enhancing our understanding of WNV as a persistent pathogen are discussed. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

The earliest known titanosauriform sauropod dinosaur and the evolution of Brachiosauridae

PubMed Central

Moine, Olivier

2017-01-01

Brachiosauridae is a clade of titanosauriform sauropod dinosaurs that includes the well-known Late Jurassic taxa Brachiosaurus and Giraffatitan. However, there is disagreement over the brachiosaurid affinities of most other taxa, and little consensus regarding the clade’s composition or inter-relationships. An unnamed partial sauropod skeleton was collected from middle–late Oxfordian (early Late Jurassic) deposits in Damparis, in the Jura department of eastern France, in 1934. Since its brief description in 1943, this specimen has been informally known in the literature as the ‘Damparis sauropod’ and ‘French Bothriospondylus’, and has been considered a brachiosaurid by most authors. If correctly identified, this would make the specimen the earliest known titanosauriform. Coupled with its relatively complete nature and the rarity of Oxfordian sauropod remains in general, this is an important specimen for understanding the early evolution of Titanosauriformes. Full preparation and description of this specimen, known from teeth, vertebrae and most of the appendicular skeleton of a single individual, recognises it as a distinct taxon: Vouivria damparisensis gen. et sp. nov. Phylogenetic analysis of a data matrix comprising 77 taxa (including all putative brachiosaurids) scored for 416 characters recovers a fairly well resolved Brachiosauridae. Vouivria is a basal brachiosaurid, confirming its status as the stratigraphically oldest known titanosauriform. Brachiosauridae consists of a paraphyletic array of Late Jurassic forms, with Europasaurus, Vouivria and Brachiosaurus recovered as successively more nested genera that lie outside of a clade comprising (Giraffatitan + Sonorasaurus) + (Lusotitan + (Cedarosaurus + Venenosaurus)). Abydosaurus forms an unresolved polytomy with the latter five taxa. The Early Cretaceous South American sauropod Padillasaurus was previously regarded as a brachiosaurid, but is here placed within Somphospondyli. A recent study

Earliest evidence of pollution by heavy metals in archaeological sites

PubMed Central

Monge, Guadalupe; Jimenez-Espejo, Francisco J.; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

2015-01-01

Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called “Anthropocene”. According to its heavy metal concentration, these sediments meet the present-day standards of “contaminated soil”. Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence. PMID:26388184

Earliest evidence of pollution by heavy metals in archaeological sites.

PubMed

Monge, Guadalupe; Jimenez-Espejo, Francisco J; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

2015-09-21

Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called "Anthropocene". According to its heavy metal concentration, these sediments meet the present-day standards of "contaminated soil". Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence.

Earliest evidence of pollution by heavy metals in archaeological sites

NASA Astrophysics Data System (ADS)

Monge, Guadalupe; Jimenez-Espejo, Francisco J.; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

2015-09-01

Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called “Anthropocene”. According to its heavy metal concentration, these sediments meet the present-day standards of “contaminated soil”. Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence.

Whole thorax irradiation of non-human primates induces persistent nuclear damage and gene expression changes in peripheral blood cells.

PubMed

Ghandhi, Shanaz A; Turner, Helen C; Shuryak, Igor; Dugan, Gregory O; Bourland, J Daniel; Olson, John D; Tooze, Janet A; Morton, Shad R; Batinic-Haberle, Ines; Cline, J Mark; Amundson, Sally A

2018-01-01

We investigated the cytogenetic and gene expression responses of peripheral blood cells of non-human primates (NHP, Macaca mulatta) that were whole-thorax irradiated with a single dose of 10 Gy. In this model, partial irradiation of NHPs in the thoracic region (Whole Thorax Lung Irradiation, WTLI) allows the study of late radiation-induced lung injury, while avoiding acute radiation syndromes related to hematopoietic and gastrointestinal injury. A transient drop in circulating lymphocytes and platelets was seen by 9 days, followed by elevations in respiratory rate, circulating neutrophils, lymphocytes, and monocytes at 60-100 days, corresponding to computed tomography (CT) and histologic evidence of pneumonitis, and elective euthanasia of four animals. To evaluate long-term DNA damage in NHP peripheral blood lymphocytes after 10 Gy WTLI, we used the cytokinesis-block micronucleus (CBMN) assay to measure chromosomal aberrations as post-mitotic micronuclei in blood samples collected up to 8 months after irradiation. Regression analysis showed significant induction of micronuclei in NHP blood cells that persisted with a gradual decline over the 8-month study period, suggesting long-term DNA damage in blood lymphocytes after WTLI. We also report transcriptomic changes in blood up to 30 days after WTLI. We isolated total RNA from peripheral blood at 3 days before and then at 2, 5 and 30 days after irradiation. We identified 1187 transcripts that were significantly changed across the 30-day time course. From changes in gene expression, we identified biological processes related to immune responses, which persisted across the 30-day study. Response to oxygen-containing compounds and bacteria were implicated by gene-expression changes at the earliest day 2 and latest, day 30 time-points. Gene expression changes suggest a persistent altered state of the immune system, specifically response to infection, for at least a month after WTLI.

Persistent arm pain is distinct from persistent breast pain following breast cancer surgery.

PubMed

Langford, Dale J; Paul, Steven M; West, Claudia; Abrams, Gary; Elboim, Charles; Levine, Jon D; Hamolsky, Deborah; Luce, Judith A; Kober, Kord M; Neuhaus, John M; Cooper, Bruce A; Aouizerat, Bradley E; Miaskowski, Christine

2014-12-01

Persistent pain following breast cancer surgery is well documented. However, it is not well characterized in terms of the anatomic site affected (ie, breast, arm). In 2 separate growth mixture modeling analyses, we identified subgroups of women (N = 398) with distinct breast pain and arm pain trajectories. The fact that these latent classes differed by anatomic site, types of tissue affected, and neural innervation patterns suggests the need for separate evaluations of these distinct persistent pain conditions. The purposes of this companion study were to identify demographic and clinical characteristics that differed between the 2 arm pain classes and determine if differences existed over time in sensitivity in the upper inner arm and axillary lymph node dissection sites, pain qualities, pain interference, and hand and arm function, as well as to compare findings with persistent breast pain. Higher occurrence rates for depression and lymphedema were found in the moderate arm pain class. Regardless of pain group membership, sensory loss was observed in the upper inner arm and axillary lymph node dissection site. Arm pain was described similarly to neuropathic pain and interfered with daily functioning. Persistent arm pain was associated with sustained impairments in shoulder mobility. For persistent breast and arm pain, changes in sensation following breast cancer surgery were notable. Persistent arm pain was associated with sustained interference with daily functioning and upper body mobility impairments. Long-term management of persistent pain following breast cancer surgery is warranted to improve the quality of survivorship for these women. Copyright © 2014 American Pain Society. Published by Elsevier Inc. All rights reserved.

PERSISTENT ARM PAIN IS DISTINCT FROM PERSISTENT BREAST PAIN FOLLOWING BREAST CANCER SURGERY

PubMed Central

Langford, Dale J.; Paul, Steven M.; West, Claudia; Abrams, Gary; Elboim, Charles; Levine, Jon D.; Hamolsky, Deborah; Luce, Judith A.; Kober, Kord M.; Neuhaus, John M.; Cooper, Bruce A.; Aouizerat, Bradley E.; Miaskowski, Christine

2014-01-01

Persistent pain following breast cancer surgery is well-documented. However, it is not well characterized in terms of the anatomic site effected (i.e., breast, arm). In two separate growth mixture modeling analyses, we identified subgroups of women (n=398) with distinct breast pain and arm pain trajectories. Based on the fact that these latent classes differed by anatomic site, types if tissue affected, and neural innervation patterns suggests the need for separate evaluations of these distinct persistent pain conditions. Purposes of this companion study were to identify demographic and clinical characteristics that differed between the two arm pain classes and determine if differences existed over time in sensitivity in the upper inner arm and axillary lymph node dissection (ALND) sites, pain qualities, pain interference, and hand and arm function; as well as to compare findings with persistent breast pain. Higher occurrence rates for depression and lymphedema were found in the Moderate Arm pain class. Regardless of pain group membership, sensory loss was observed in the upper inner arm and ALND site. Arm pain was described similarly to neuropathic pain and interfered with daily functioning. Persistent arm pain was associated with sustained impairments in shoulder mobility. Perspective: For persistent breast and arm pain, changes in sensation following breast cancer surgery were notable. Persistent arm pain was associated with sustained interference with daily functioning and upper body mobility impairments. Long-term management of persistent pain following breast cancer surgery is warranted to improve the quality of survivorship for these women. PMID:25439319

The earliest maize from San Marcos Tehuacán is a partial domesticate with genomic evidence of inbreeding

PubMed Central

Vallebueno-Estrada, Miguel; Rodríguez-Arévalo, Isaac; Rougon-Cardoso, Alejandra; Martínez González, Javier; García Cook, Angel; Vielle-Calzada, Jean-Philippe

2016-01-01

Pioneering archaeological expeditions lead by Richard MacNeish in the 1960s identified the valley of Tehuacán as an important center of early Mesoamerican agriculture, providing by far the widest collection of ancient crop remains, including maize. In 2012, a new exploration of San Marcos cave (Tehuacán, Mexico) yielded nonmanipulated maize specimens dating at a similar age of 5,300–4,970 calibrated y B.P. On the basis of shotgun sequencing and genomic comparisons to Balsas teosinte and modern maize, we show herein that the earliest maize from San Marcos cave was a partial domesticate diverging from the landraces and containing ancestral allelic variants that are absent from extant maize populations. Whereas some domestication loci, such as teosinte branched1 (tb1) and brittle endosperm2 (bt2), had already lost most of the nucleotide variability present in Balsas teosinte, others, such as teosinte glume architecture1 (tga1) and sugary1 (su1), conserved partial levels of nucleotide variability that are absent from extant maize. Genetic comparisons among three temporally convergent samples revealed that they were homozygous and identical by descent across their genome. Our results indicate that the earliest maize from San Marcos was already inbred, opening the possibility for Tehuacán maize cultivation evolving from reduced founder populations of isolated and perhaps self-pollinated individuals. PMID:27872313

The earliest maize from San Marcos Tehuacán is a partial domesticate with genomic evidence of inbreeding.

PubMed

Vallebueno-Estrada, Miguel; Rodríguez-Arévalo, Isaac; Rougon-Cardoso, Alejandra; Martínez González, Javier; García Cook, Angel; Montiel, Rafael; Vielle-Calzada, Jean-Philippe

2016-12-06

Pioneering archaeological expeditions lead by Richard MacNeish in the 1960s identified the valley of Tehuacán as an important center of early Mesoamerican agriculture, providing by far the widest collection of ancient crop remains, including maize. In 2012, a new exploration of San Marcos cave (Tehuacán, Mexico) yielded nonmanipulated maize specimens dating at a similar age of 5,300-4,970 calibrated y B.P. On the basis of shotgun sequencing and genomic comparisons to Balsas teosinte and modern maize, we show herein that the earliest maize from San Marcos cave was a partial domesticate diverging from the landraces and containing ancestral allelic variants that are absent from extant maize populations. Whereas some domestication loci, such as teosinte branched1 (tb1) and brittle endosperm2 (bt2), had already lost most of the nucleotide variability present in Balsas teosinte, others, such as teosinte glume architecture1 (tga1) and sugary1 (su1), conserved partial levels of nucleotide variability that are absent from extant maize. Genetic comparisons among three temporally convergent samples revealed that they were homozygous and identical by descent across their genome. Our results indicate that the earliest maize from San Marcos was already inbred, opening the possibility for Tehuacán maize cultivation evolving from reduced founder populations of isolated and perhaps self-pollinated individuals.

Numeric invariants from multidimensional persistence

DOE PAGES

Skryzalin, Jacek; Carlsson, Gunnar

2017-05-19

Topological data analysis is the study of data using techniques from algebraic topology. Often, one begins with a finite set of points representing data and a “filter” function which assigns a real number to each datum. Using both the data and the filter function, one can construct a filtered complex for further analysis. For example, applying the homology functor to the filtered complex produces an algebraic object known as a “one-dimensional persistence module”, which can often be interpreted as a finite set of intervals representing various geometric features in the data. If one runs the above process incorporating multiple filtermore » functions simultaneously, one instead obtains a multidimensional persistence module. Unfortunately, these are much more difficult to interpret. In this article, we analyze the space of multidimensional persistence modules from the perspective of algebraic geometry. First we build a moduli space of a certain subclass of easily analyzed multidimensional persistence modules, which we construct specifically to capture much of the information which can be gained by using multidimensional persistence instead of one-dimensional persistence. Fruthermore, we argue that the global sections of this space provide interesting numeric invariants when evaluated against our subclass of multidimensional persistence modules. Finally, we extend these global sections to the space of all multidimensional persistence modules and discuss how the resulting numeric invariants might be used to study data. This paper extends the results of Adcock et al. (Homol Homotopy Appl 18(1), 381–402, 2016) by constructing numeric invariants from the computation of a multidimensional persistence module as given by Carlsson et al. (J Comput Geom 1(1), 72–100, 2010).« less

One of the Earliest Accounts of Head Wounds in Firdaws al-Ḥikma by al-Ṭabarī from the 9th Century.

PubMed

Acıduman, Ahmet; Tuzcu, Kemal; Belen, Deniz

2017-11-01

To present the first Arabic text on suturing scalp wounds. A related section entitled "On the wounds in the head" from the book Firdaws al-Ḥikma (Paradise of the Wisdom) written by al-Ṭabarī in the 9th century was identified and analyzed. This work was one of the earliest medical compendiums in the Islamic world during the medieval period. A printed copy of Firdaws al-Ḥikma edited by Muḥammad Zubayr al-Ṣiddīqī was examined, and findings were compared with relevant knowledge in the literature. A notable part of this text is based on appropriate closure of scalp wounds using sutures. Before this work, only the well-known Indian medical book Suśruta-Saṃhitā had mentioned closure of scalp wounds using sutures. In his work, al-Ṭabarī recommended using materials made of silk or linen for suturing. He additionally proposed some recipes that have a coating feature that prevents bleeding from the wound after it was closed properly. He also dealt with persistent swelling and provided formulas for solving the problem with special compositions. Firdaws al-Ḥikma is a noteworthy work in the history of medicine, and it includes a unique chapter on head wounds. To the best of our knowledge, this is the first mention of suturing scalp cuts in Arabic literature and the second reference in medical literature after the Indian work Suśruta-Saṃhitā. Copyright © 2017 Elsevier Inc. All rights reserved.

Bilingual Readiness in Earliest School Years; A Curriculum Demonstration Project. Bilingual Readiness in Primary Grades; An Early Childhood Demonstration Project. Final Report.

ERIC Educational Resources Information Center

Finocchiaro, Mary; King, Paul F.

These two curriculum demonstration projects on bilingual readiness in the earliest school years contain many similarities. Both were formed on the thesis that young children can and will learn a second language readily and that the urban classroom mixture of Spanish-speaking, English-speaking, and Negro-dialect speaking children can be capitalized…

Drought Persistence in Models and Observations

NASA Astrophysics Data System (ADS)

Moon, Heewon; Gudmundsson, Lukas; Seneviratne, Sonia

2017-04-01

Many regions of the world have experienced drought events that persisted several years and caused substantial economic and ecological impacts in the 20th century. However, it remains unclear whether there are significant trends in the frequency or severity of these prolonged drought events. In particular, an important issue is linked to systematic biases in the representation of persistent drought events in climate models, which impedes analysis related to the detection and attribution of drought trends. This study assesses drought persistence errors in global climate model (GCM) simulations from the 5th phase of Coupled Model Intercomparison Project (CMIP5), in the period of 1901-2010. The model simulations are compared with five gridded observational data products. The analysis focuses on two aspects: the identification of systematic biases in the models and the partitioning of the spread of drought-persistence-error into four possible sources of uncertainty: model uncertainty, observation uncertainty, internal climate variability and the estimation error of drought persistence. We use monthly and yearly dry-to-dry transition probabilities as estimates for drought persistence with drought conditions defined as negative precipitation anomalies. For both time scales we find that most model simulations consistently underestimated drought persistence except in a few regions such as India and Eastern South America. Partitioning the spread of the drought-persistence-error shows that at the monthly time scale model uncertainty and observation uncertainty are dominant, while the contribution from internal variability does play a minor role in most cases. At the yearly scale, the spread of the drought-persistence-error is dominated by the estimation error, indicating that the partitioning is not statistically significant, due to a limited number of considered time steps. These findings reveal systematic errors in the representation of drought persistence in current

Persistent luminescence nanothermometers

NASA Astrophysics Data System (ADS)

Martín Rodríguez, Emma; López-Peña, Gabriel; Montes, Eduardo; Lifante, Ginés; García Solé, José; Jaque, Daniel; Diaz-Torres, Luis Armando; Salas, Pedro

2017-08-01

Persistent phosphorescence nanoparticles emitting in the red and near-infrared spectral regions are strongly demanded as contrast nanoprobes for autofluorescence free bioimaging and biosensing. In this work, we have developed Sr4Al14O25:Eu2+, Cr3+, Nd3+ nanopowders that produce persistent red phosphorescence peaking at 694 nm generated by Cr3+ ions. This emission displays temperature sensitivity in the physiological temperature range (20-60 °C), which makes these nanoparticles potentially useful as fluorescence (contactless) nanothermometers operating without requiring optical excitation. Nd3+ ions, which act as shallow electron traps for the red Cr3+ persistent emission, also display infrared emission bands, extending the fluorescence imaging capability to the second biological window. This unique combination of properties makes these nanoparticles multifunctional luminescent probes with great potential applications in nanomedicine.

STEM Field Persistence: The Impact of Engagement on Postsecondary STEM Persistence for Underrepresented Minority Students

ERIC Educational Resources Information Center

Flynn, Daniel T.

2016-01-01

Persistence studies in science, technology, engineering, and math (STEM) fields indicate that the pipeline to degree attainment is "leaky" and underrepresented minorities are not persisting in the STEM fields. Those students who do not persist in the STEM fields either migrate to other fields of study or drop out of higher education…

Pulses of middle Eocene to earliest Oligocene climatic deterioration in southern California and the Gulf Coast

USGS Publications Warehouse

Frederiksen, N.O.

1991-01-01

A general deterioration of terrestrial climate took place during middle Eocene to earliest Oligocene time in southern California and in the Gulf Coast. Pollen data, calibrated by calcareous nannofossil ages, indicate four events of rapid floral and/or vegetational change among angiosperms during this time interval. The events can be correlated between the two regions even though these regions lay within different floristic provinces, and each event of angiosperm change is interpreted to indicate a pulse of rapid climatic shift. The most distinct of these events is the Middle Eocene Diversity Decline, which resulted from a peak in last appearances (extinctions, emigrations) centered in the early Bartonian. -from Author

Earliest evidence for equid bit wear in the ancient Near East: The "ass" from Early Bronze Age Tell eṣ-Ṣâfi/Gath, Israel

PubMed Central

Shai, Itzhaq; Greenfield, Tina L.; Arnold, Elizabeth R.; Brown, Annie; Eliyahu, Adi; Maeir, Aren M.

2018-01-01

Analysis of a sacrificed and interred domestic donkey from an Early Bronze Age (EB) IIIB (c. 2800–2600 BCE) domestic residential neighborhood at Tell eṣ-Ṣâfi/Gath, Israel, indicate the presence of bit wear on the Lower Premolar 2 (LPM2). This is the earliest evidence for the use of a bit among early domestic equids, and in particular donkeys, in the Near East. The mesial enamel surfaces on both the right and left LPM2 of the particular donkey in question are slightly worn in a fashion that suggests that a dental bit (metal, bone, wood, etc.) was used to control the animal. Given the secure chronological context of the burial (beneath the floor of an EB IIIB house), it is suggested that this animal provides the earliest evidence for the use of a bit on an early domestic equid from the Near East. PMID:29768439

Earliest evidence for equid bit wear in the ancient Near East: The "ass" from Early Bronze Age Tell eṣ-Ṣâfi/Gath, Israel.

PubMed

Greenfield, Haskel J; Shai, Itzhaq; Greenfield, Tina L; Arnold, Elizabeth R; Brown, Annie; Eliyahu, Adi; Maeir, Aren M

2018-01-01

Analysis of a sacrificed and interred domestic donkey from an Early Bronze Age (EB) IIIB (c. 2800-2600 BCE) domestic residential neighborhood at Tell eṣ-Ṣâfi/Gath, Israel, indicate the presence of bit wear on the Lower Premolar 2 (LPM2). This is the earliest evidence for the use of a bit among early domestic equids, and in particular donkeys, in the Near East. The mesial enamel surfaces on both the right and left LPM2 of the particular donkey in question are slightly worn in a fashion that suggests that a dental bit (metal, bone, wood, etc.) was used to control the animal. Given the secure chronological context of the burial (beneath the floor of an EB IIIB house), it is suggested that this animal provides the earliest evidence for the use of a bit on an early domestic equid from the Near East.

Changes of lysosomes in the earliest stages of the development of atherosclerosis.

PubMed

Bobryshev, Yuri V; Shchelkunova, Tatyana A; Morozov, Ivan A; Rubtsov, Petr M; Sobenin, Igor A; Orekhov, Alexander N; Smirnov, Alexander N

2013-05-01

One of hypotheses of atherosclerosis is based on a presumption that the zones prone to the development of atherosclerosis contain lysosomes which are characterized by enzyme deficiency and thus, are unable to dispose of lipoproteins. The present study was undertaken to investigate the characteristics and changes of lysosomes in the earliest stages of the development of atherosclerosis. Electron microscopic immunocytochemistry revealed that there were certain changes in the distribution of CD68 antigen in lysosomes along the 'normal intima-initial lesion-fatty streak' sequence. There were no significant changes found in the key mRNAs encoding for the components of endosome/lysosome compartment in initial atherosclerotic lesions, but in fatty streaks, the contents of EEA1 and Rab5a mRNAs were found to be diminished while the contents of CD68 and p62 mRNAs were increased, compared with the intact tissue. The study reinforces a view that changes occurring in lysosomes play a role in atherogenesis from the very earlier stages of the disease. © 2013 The Authors. Published by Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

The earliest mollusc dominated seep fauna from the Early Jurassic of Argentina

NASA Astrophysics Data System (ADS)

Kaim, Andrzej; Jenkins, Robert; Parent, Horacio; Garrido, Alberto; Moriya, Kazuhiro

2015-04-01

The earliest mollusc dominated seep fauna from the Early Jurassic of Argentina Andrzej Kaim, Robert G. Jenkins, Horacio Parent, Alberto C. Garrido The hydrocarbon seep deposits are known from Early Jurassic of Argentina since the report of Gomez-Perez (2003). The latter author identified very negative δ13C values (down to -33) and several fabrics typical for seep carbonates. Nevertheless she identified no macrofaunal assemblages apart from worm tubes. We re-visited the locality of Gomez-Perez (named here La Elina) and we were able to collect several molluscs associated with the seep carbonate. The most common and diversified are molluscs and worm tubes. We identified at least three species of gastropods, including the oldest-known species of neomphalids, lucinid and protobranch bivalves and numerous ammonoids. Unlike another known Early Jurassic seep from Oregon and the only Late Triassic seep (also from Oregon) there are no brachiopods associated with this seep. Therefore we consider the seep at La Elina as the oldest seep of modern aspect where the fauna is dominated by molluscs and not brachiopods.

Persistent homology and non-Gaussianity

NASA Astrophysics Data System (ADS)

Cole, Alex; Shiu, Gary

2018-03-01

In this paper, we introduce the topological persistence diagram as a statistic for Cosmic Microwave Background (CMB) temperature anisotropy maps. A central concept in 'Topological Data Analysis' (TDA), the idea of persistence is to represent a data set by a family of topological spaces. One then examines how long topological features 'persist' as the family of spaces is traversed. We compute persistence diagrams for simulated CMB temperature anisotropy maps featuring various levels of primordial non-Gaussianity of local type. Postponing the analysis of observational effects, we show that persistence diagrams are more sensitive to local non-Gaussianity than previous topological statistics including the genus and Betti number curves, and can constrain Δ fNLloc= 35.8 at the 68% confidence level on the simulation set, compared to Δ fNLloc= 60.6 for the Betti number curves. Given the resolution of our simulations, we expect applying persistence diagrams to observational data will give constraints competitive with those of the Minkowski Functionals. This is the first in a series of papers where we plan to apply TDA to different shapes of non-Gaussianity in the CMB and Large Scale Structure.

Persistent Distress after Water Contamination.

PubMed

Schade, Charles P; Gupta, Rahul; Jha, Ayan; Wright, Nasandra

2016-01-01

A chemical spill contaminated the public water supply of Charleston, West Virginia in January 2014 for at least a week. Psychological distress is common after disasters. We surveyed the exposed population to assess psychological distress during and three months after the incident. We inquired about stressors that might predict distress, adequacy of communication from public officials, and use of the water supply and perceptions of its safety three months after the incident. Twenty six percent of interviewees had persistent symptoms of distress. Female sex, negative household experiences during the episode (especially having someone sick), and poor perception of communication increased odds of persistent distress. Households of respondents without persistent distress were significantly more likely to report drinking tap water (RR=1.95) than those with persistent distress. Distress in Charleston area residents persisted and may have resulted in continuing mistrust of the water supply.

Predicting Which Childhood Memories Persist: Contributions of Memory Characteristics

ERIC Educational Resources Information Center

Peterson, Carole; Morris, Gwynn; Baker-Ward, Lynne; Flynn, Susan

2014-01-01

This investigation identified memory-level predictors of the survivability of 4- to 13-year-old children's earliest recollections over a 2-year period. Data previously reported by Peterson, Warren, and Short (2011) were coded for inclusion of emotion terms and thematic, chronological, and contextual narrative coherence. In addition, the…

Ca Isotopes Fingerprinting the Earliest Crustal Evolution

NASA Astrophysics Data System (ADS)

Kreissig, K.; Elliott, T. R.

2001-12-01

The mechanisms of continent formation remain unclear and can be explained in two contrasting ways, using either a steady state crustal growth model involving massive crustal recycling or continuous crustal growth models. Recent developments in mass spectrometry manifest in the new Finnigan-Triton allow Ca isotopic measurements precise enough to use the K-Ca isotope system to address the problem of early Archaean crustal evolution. Due to a strong fractionation of 40K and 40Ca during continent formation and a non-linear growth of 40Ca, Archaean continental crust should show radiogenic initial Ca isotopic composition if large volumes of it have already been existed 3.6 Ga ago. Simple 15-step calculations predict a difference in 40Ca /44Ca of 9 epsilon units at 3.6 Ga between the two crustal growth models. To test this, as well as to study the earliest crust formation processes, plagioclase separates from Archaean provinces reflecting the initial Ca isotopic composition and a range of different whole rock samples have been analysed. Preliminary data for ~ 3.6 Ga old TTGs from Zimbabwe show 40Ca /44Ca indistinguishable from the mantle. This is in agreement with rather chondritic initial Sr and Nd data and might reflect a short residence time of the juvenile mafic oceanic crust before partial melting forming the first continental crust. In contrast, the first results for 3.65 Ga old samples from the Itsaq Gneiss Complex of southern West Greenland yield a more evolved radiogenic Ca signature. This can be interpreted in two different ways. Either as partial melting of juvenile mafic crust shortly after its formation but incorporating already existing crust as also suggested by the existence of older inherited zircons in these rocks and negative ɛ Hf values. Partial melting of mafic oceanic crust long after its formation so that 40K and 40Ca had time to evolve would be an alternative explanation. Importantly, there is no evidence so far for high growth and recycling rates

Interaction of Staphylococcus aureus persister cells with the host when in a persister state and following awakening.

PubMed

Mina, Elin G; Marques, Cláudia N H

2016-08-10

Persister cells, a tolerant cell sub-population, are commonly associated with chronic and recurrent infections. However, little is known about their ability to actually initiate or establish an infection, become virulent and cause pathogenicity within a host. Here we investigated whether Staphylococcus aureus persister cells initiate an infection and are recognized by macrophages, while in a persister cell status, and upon awakening due to exposure to cis-2-decenoic acid (cis-DA). Our results show that S. aureus persister cells are not able to initiate infections in A. thaliana and present significantly reduced virulence towards C. elegans compared to total populations. In contrast, awakened S. aureus persister cells are able to initiate infections in A. thaliana and in C. elegans albeit, with lower mortality than total population. Furthermore, exposure of S. aureus persister cells to cis-DA led to a loss of tolerance to ciprofloxacin, and an increase of the bacterial fluorescence to levels found in total population. In addition, macrophage engulfment of persister cells was significantly lower than engulfment of total population, both before and following awakening. Overall our findings indicate that upon awakening of a persister population the cells regain their ability to infect hosts despite the absence of an increased immune response.

Earliest evidence of dental caries manipulation in the Late Upper Palaeolithic

PubMed Central

Oxilia, Gregorio; Peresani, Marco; Romandini, Matteo; Matteucci, Chiara; Spiteri, Cynthianne Debono; Henry, Amanda G.; Schulz, Dieter; Archer, Will; Crezzini, Jacopo; Boschin, Francesco; Boscato, Paolo; Jaouen, Klervia; Dogandzic, Tamara; Broglio, Alberto; Moggi-Cecchi, Jacopo; Fiorenza, Luca; Hublin, Jean-Jacques; Kullmer, Ottmar; Benazzi, Stefano

2015-01-01

Prehistoric dental treatments were extremely rare, and the few documented cases are known from the Neolithic, when the adoption of early farming culture caused an increase of carious lesions. Here we report the earliest evidence of dental caries intervention on a Late Upper Palaeolithic modern human specimen (Villabruna) from a burial in Northern Italy. Using Scanning Electron Microscopy we show the presence of striations deriving from the manipulation of a large occlusal carious cavity of the lower right third molar. The striations have a “V”-shaped transverse section and several parallel micro-scratches at their base, as typically displayed by cutmarks on teeth. Based on in vitro experimental replication and a complete functional reconstruction of the Villabruna dental arches, we confirm that the identified striations and the associated extensive enamel chipping on the mesial wall of the cavity were produced ante-mortem by pointed flint tools during scratching and levering activities. The Villabruna specimen is therefore the oldest known evidence of dental caries intervention, suggesting at least some knowledge of disease treatment well before the Neolithic. This study suggests that primitive forms of carious treatment in human evolution entail an adaptation of the well-known toothpicking for levering and scratching rather than drilling practices. PMID:26179739

The Chachil Limestone (Pliensbachian-earliest Toarcian) Neuquén Basin, Argentina: U-Pb age calibration and its significance on the Early Jurassic evolution of southwestern Gondwana

NASA Astrophysics Data System (ADS)

Leanza, H. A.; Mazzini, A.; Corfu, F.; Llambías, E. J.; Svensen, H.; Planke, S.; Galland, O.

2013-03-01

New radiometric U-Pb ages obtained on zircon crystals from Early Jurassic ash layers found within beds of the Chachil Limestone at its type locality in the Chachil depocentre (southern Neuquén Basin) confirm a Pliensbachian age (186.0 ± 0.4 Ma). Additionally, two ash layers found in limestone beds in Chacay Melehue at the Cordillera del Viento depocentre (central Neuquén Basin) gave Early Pliensbachian (185.7 ± 0.4 Ma) and earliest Toarcian (182.3 ± 0.4 Ma) U-Pb zircon ages. Based on these new datings and regional geological observations, we propose that the limestones cropping out at Chacay Melehue are correlatable with the Chachil Limestone. Recent data by other authors from limestones at Serrucho creek in the upper Puesto Araya Formation (Valenciana depocentre, southern Mendoza) reveal ages of 182.16 ± 0.6 Ma. Based on these new evidences, we consider the Chachil Limestone an important Early Jurassic stratigraphic marker, representing an almost instantaneous widespread flooding episode in western Gondwana. The unit marks the initiation in the Neuquén Basin of the Cuyo Group, followed by widespread black shale deposition. Accordingly, these limestones can be regarded as the natural seal of the Late Triassic -earliest Jurassic Precuyano Cycle, which represents the infill of halfgrabens and/or grabens related to a strong extensional regime. Paleontological evidence supports that during Pliensbachian-earliest Toarcian times these limestones were deposited in western Gondwana in marine warm water environments.

The Earliest Reference to ADHD in the Medical Literature? Melchior Adam Weikard's Description in 1775 of "Attention Deficit" (Mangel der Aufmerksamkeit, Attentio Volubilis)

ERIC Educational Resources Information Center

Barkley, Russell A.; Peters, Helmut

2012-01-01

Objective: The present article reports on the discovery and translation of a chapter in a 1775 medical textbook by the German physician, Melchior Adam Weikard, which describes attention disorders. This article is believed to be the earliest reference to the syndrome that today is known as attention deficit hyperactivity disorder, or ADHD. Method:…

Epigenetic regulation of persistent pain

PubMed Central

Bai, Guang; Ren, Ke; Dubner, Ronald

2014-01-01

Persistent or chronic pain is tightly associated with various environmental changes and linked to abnormal gene expression within cells processing nociceptive signaling. Epigenetic regulation governs gene expression in response to environmental cues. Recent animal model and clinical studies indicate that epigenetic regulation plays an important role in the development/maintenance of persistent pain and, possibly the transition of acute pain to chronic pain, thus shedding light in a direction for development of new therapeutics for persistent pain. PMID:24948399

Earliest land plants created modern levels of atmospheric oxygen.

PubMed

Lenton, Timothy M; Dahl, Tais W; Daines, Stuart J; Mills, Benjamin J W; Ozaki, Kazumi; Saltzman, Matthew R; Porada, Philipp

2016-08-30

The progressive oxygenation of the Earth's atmosphere was pivotal to the evolution of life, but the puzzle of when and how atmospheric oxygen (O2) first approached modern levels (∼21%) remains unresolved. Redox proxy data indicate the deep oceans were oxygenated during 435-392 Ma, and the appearance of fossil charcoal indicates O2 >15-17% by 420-400 Ma. However, existing models have failed to predict oxygenation at this time. Here we show that the earliest plants, which colonized the land surface from ∼470 Ma onward, were responsible for this mid-Paleozoic oxygenation event, through greatly increasing global organic carbon burial-the net long-term source of O2 We use a trait-based ecophysiological model to predict that cryptogamic vegetation cover could have achieved ∼30% of today's global terrestrial net primary productivity by ∼445 Ma. Data from modern bryophytes suggests this plentiful early plant material had a much higher molar C:P ratio (∼2,000) than marine biomass (∼100), such that a given weathering flux of phosphorus could support more organic carbon burial. Furthermore, recent experiments suggest that early plants selectively increased the flux of phosphorus (relative to alkalinity) weathered from rocks. Combining these effects in a model of long-term biogeochemical cycling, we reproduce a sustained +2‰ increase in the carbonate carbon isotope (δ(13)C) record by ∼445 Ma, and predict a corresponding rise in O2 to present levels by 420-400 Ma, consistent with geochemical data. This oxygen rise represents a permanent shift in regulatory regime to one where fire-mediated negative feedbacks stabilize high O2 levels.

Earliest land plants created modern levels of atmospheric oxygen

NASA Astrophysics Data System (ADS)

Lenton, Timothy M.; Dahl, Tais W.; Daines, Stuart J.; Mills, Benjamin J. W.; Ozaki, Kazumi; Saltzman, Matthew R.; Porada, Philipp

2016-08-01

The progressive oxygenation of the Earth’s atmosphere was pivotal to the evolution of life, but the puzzle of when and how atmospheric oxygen (O2) first approached modern levels (˜21%) remains unresolved. Redox proxy data indicate the deep oceans were oxygenated during 435-392 Ma, and the appearance of fossil charcoal indicates O2 >15-17% by 420-400 Ma. However, existing models have failed to predict oxygenation at this time. Here we show that the earliest plants, which colonized the land surface from ˜470 Ma onward, were responsible for this mid-Paleozoic oxygenation event, through greatly increasing global organic carbon burial—the net long-term source of O2. We use a trait-based ecophysiological model to predict that cryptogamic vegetation cover could have achieved ˜30% of today’s global terrestrial net primary productivity by ˜445 Ma. Data from modern bryophytes suggests this plentiful early plant material had a much higher molar C:P ratio (˜2,000) than marine biomass (˜100), such that a given weathering flux of phosphorus could support more organic carbon burial. Furthermore, recent experiments suggest that early plants selectively increased the flux of phosphorus (relative to alkalinity) weathered from rocks. Combining these effects in a model of long-term biogeochemical cycling, we reproduce a sustained +2‰ increase in the carbonate carbon isotope (δ13C) record by ˜445 Ma, and predict a corresponding rise in O2 to present levels by 420-400 Ma, consistent with geochemical data. This oxygen rise represents a permanent shift in regulatory regime to one where fire-mediated negative feedbacks stabilize high O2 levels.

Revisiting the earliest electrophysiological correlate of familiar face recognition.

PubMed

Huang, Wanyi; Wu, Xia; Hu, Liping; Wang, Lei; Ding, Yulong; Qu, Zhe

2017-10-01

The present study used event-related potentials (ERPs) to reinvestigate the earliest face familiarity effect (FFE: ERP differences between familiar and unfamiliar faces) that genuinely reflects cognitive processes underlying recognition of familiar faces in long-term memory. To trigger relatively early FFEs, participants were required to categorize upright and inverted famous faces and unknown faces in a task that placed high demand on face recognition. More importantly, to determine whether an observed FFE was linked to on-line face recognition, systematical investigation about the relationship between the FFE and behavioral performance of face recognition was conducted. The results showed significant FFEs on P1, N170, N250, and P300 waves. The FFEs on occipital P1 and N170 (<200ms) showed reversed polarities for upright and inverted faces, and were not correlated with any behavioral measure (accuracy, response time) or modulated by learning, indicating that they might merely reflect low-level visual differences between face sets. In contrast, the later FFEs on occipito-temporal N250 (~230ms) and centro-parietal P300 (~350ms) showed consistent polarities for upright and inverted faces. The N250 FFE was individually correlated with recognition speed for upright faces, and could be obtained for inverted faces through learning. The P300 FFE was also related to behavior in many aspects. These findings provide novel evidence supporting that cognitive discrimination of familiar and unfamiliar faces starts no less than 200ms after stimulus onset, and the familiarity effect on N250 may be the first electrophysiological correlate underlying recognition of familiar faces in long-term memory. Copyright © 2017 Elsevier B.V. All rights reserved.

[From persistence to symbiosis of microorganisms].

PubMed

Bukharin, O V

2012-01-01

Primary results of study of problem of microorganism persistence over the last 2 decades on 7 all-Russian conferences in Orenburg are examined in the article. Milestones of both fundamental research and practically significant studies are designated, the role of persistent potential of microorganisms in infectious pathology is evaluated. The emerging turn of studies from persistence to symbiosis is consonant with the idea of international project "Human microbiom" and allows to use the persistent potential of microorganisms as one of the instruments of resolving issues of infectology.

Persistence-Retention. Snapshot™ Report, Spring 2014

ERIC Educational Resources Information Center

National Student Clearinghouse, 2014

2014-01-01

This snapshot report provides information on student persistence and retention rates for Spring 2014. Data is presented in tabular format on the following: (1) First-Year Persistence and Retention Rates by Starting Enrollment Intensity (all institutional sectors); (2) First-Year Persistence and Retention Rates by Age at College Entry (all…

Persistence of interest in science, technology, engineering and mathematics: An analysis of persisting and non-persisting students

NASA Astrophysics Data System (ADS)

White, Jeffry L.

While there has been an increase in enrollment, interest in science, technology, engineering, and mathematics (STEM) has been declining on college campuses since 1967. Higher enrollment does not transfer to an increase in the number of minorities in the STEM fields. The majority-minority enrollment ratio is nearly 2:1 but the gap widens to 4:1 when it comes to graduation. In fact, underrepresented minorities (URM) earned only 12% of the STEM degrees awarded in 1998. When the higher attrition and lower graduation rates of URM are scrutinized, upwards of 60% changed majors or dropped out of STEM. Further investigation reveals the most frequently cited reasons for departure were loss of initial interest, developed a greater interest in another field, or were turned off by the STEM disciplines. A primarily exploratory study was conducted into the conditions necessary for academic interest in the STEM fields to persist. A model based on student engagement (Astin, 1977) and interest operations (Prenzel, 1988a) theories was used with a random sample of URM at universities participating in the Ohio Science and Engineering Alliance. Survey research was employed to investigate interest development and the effect of student retention programs and activities on such interest. The latter part of the study could not be fully examined when 95% reported not utilizing retention services. For the section on interest, an online survey using a 5-point Likert scale was validated using principal components analysis. A binominal logistic regression was used to predict membership in one of two possible groups: persisters and students at-risk for not persisting. The major conclusions are: (1) While 3 variables (feelings, learning and difficulty) were statistically significant only one, feelings was substantively significant. (2) Persistence increased 80.9% for each 1-unit increase in feelings and 9.9% for learning. (3) Persistence decreased 19.8% for each one-unit increase in difficulty

Mean wind speed persistence over China

NASA Astrophysics Data System (ADS)

Jiang, Lei

2018-07-01

The wind speed persistence is an important factor in the assessment of wind energy potential. In this paper, we explore the persistence of Mean Wind Speed (MWS) with many years of record using Detrended Fluctuation Analysis (DFA) over China. The results illustrate that there exist irregular high-frequency fluctuations for daily MWS anomaly records. Long-term persistence of MWS is found for all meteorological observed sites. We also make some numerical tests in order to verify the significance of long-term persistence by shuffling the data records many times. These facts prove that the MWS anomaly records have long-term persistence over all the stations in China. The mean value 0.64 in DFA-exponents for all stations over China is also obviously higher than the value 0.53 according to interval threshold of 95% confidence level after shuffling the MWS records many times. In addition, the values of scaling exponent vary from station to station over China. Long-term persistence of MWS in spatial distributions seems to be downward trends from east to west China. Many factors may affect long-term persistence of MWS such as southwest monsoon, Tibetan Plateau landform and atmosphere-ocean-land interaction and so on. Possible physical mechanism need further analysis in the future.

Persistence-Retention. Snapshot™ Report, Spring 2015

ERIC Educational Resources Information Center

National Student Clearinghouse, 2015

2015-01-01

This Snapshot Report offers information on student persistence and retention rates for 2009-2013. It offers data on the following: (1) First-Year Persistence and Retention Rates for Students Who Start College at Four-Year Private Nonprofit Institutions; (2) First-Year Persistence and Retention Rates for Students Who Start College at Four-Year…

Persistence Characteristics of Australian Rainfall Anomalies

NASA Astrophysics Data System (ADS)

Simmonds, Ian; Hope, Pandora

1997-05-01

Using 79 years (1913-1991) of Australian monthly precipitation data we examined the nature of the persistence of rainfall anomalies. Analyses were performed for four climate regions covering the country, as well as for the entire Australian continent. We show that rainfall over these regions has high temporal variability and that annual rainfall amounts over all five sectors vary in phase and are, with the exception of the north-west region, significantly correlated with the Southern Oscillation Index (SOI). These relationships were particularly strong during the spring season.It is demonstrated that Australian rainfall exhibits statistically significant persistence on monthly, seasonal, and (to a limited extent) annual time-scales, up to lags of 3 months and one season and 1 year. The persistence showed strong seasonal dependence, with each of the five regions showing memory out to 4 or 5 months from winter and spring. Many aspects of climate in the Australasian region are known to have undergone considerable changes about 1950. We show this to be true for persistence also; its characteristics identified for the entire record were present during the 1951--1980 period, but virtually disappeared in the previous 30-year period.Much of the seasonal distribution of rainfall persistence on monthly time-scales, particularly in the east, is due to the influence of the SOI. However, most of the persistence identified in winter and spring in the north-west is independent of the ENSO phenomenon.Rainfall anomalies following extreme dry and wet months, seasons and years (lowest and highest two deciles) persisted more than would be expected by chance. For monthly extreme events this was more marked in the winter semester for the wet events, except in the south-east region. In general, less persistence was found for the extreme seasons. Although the persistence of dry years was less than would have been expected by chance, the wet years appear to display persistence.

The Comoros Show the Earliest Austronesian Gene Flow into the Swahili Corridor.

PubMed

Brucato, Nicolas; Fernandes, Veronica; Mazières, Stéphane; Kusuma, Pradiptajati; Cox, Murray P; Ng'ang'a, Joseph Wainaina; Omar, Mohammed; Simeone-Senelle, Marie-Claude; Frassati, Coralie; Alshamali, Farida; Fin, Bertrand; Boland, Anne; Deleuze, Jean-Francois; Stoneking, Mark; Adelaar, Alexander; Crowther, Alison; Boivin, Nicole; Pereira, Luisa; Bailly, Pascal; Chiaroni, Jacques; Ricaut, François-Xavier

2018-01-04

At the dawn of the second millennium, the expansion of the Indian Ocean trading network aligned with the emergence of an outward-oriented community along the East African coast to create a cosmopolitan cultural and trading zone known as the Swahili Corridor. On the basis of analyses of new genome-wide genotyping data and uniparental data in 276 individuals from coastal Kenya and the Comoros islands, along with large-scale genetic datasets from the Indian Ocean rim, we reconstruct historical population dynamics to show that the Swahili Corridor is largely an eastern Bantu genetic continuum. Limited gene flows from the Middle East can be seen in Swahili and Comorian populations at dates corresponding to historically documented contacts. However, the main admixture event in southern insular populations, particularly Comorian and Malagasy groups, occurred with individuals from Island Southeast Asia as early as the 8 th century, reflecting an earlier dispersal from this region. Remarkably, our results support recent archaeological and linguistic evidence-based suggestions that the Comoros archipelago was the earliest location of contact between Austronesian and African populations in the Swahili Corridor. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Earliest floral grave lining from 13,700-11,700-y-old Natufian burials at Raqefet Cave, Mt. Carmel, Israel.

PubMed

Nadel, Dani; Danin, Avinoam; Power, Robert C; Rosen, Arlene M; Bocquentin, Fanny; Tsatskin, Alexander; Rosenberg, Danny; Yeshurun, Reuven; Weissbrod, Lior; Rebollo, Noemi R; Barzilai, Omry; Boaretto, Elisabetta

2013-07-16

Flowering plants possess mechanisms that stimulate positive emotional and social responses in humans. It is difficult to establish when people started to use flowers in public and ceremonial events because of the scarcity of relevant evidence in the archaeological record. We report on uniquely preserved 13,700-11,700-y-old grave linings made of flowers, suggesting that such use began much earlier than previously thought. The only potentially older instance is the questionable use of flowers in the Shanidar IV Neanderthal grave. The earliest cemeteries (ca. 15,000-11,500 y ago) in the Levant are known from Natufian sites in northern Israel, where dozens of burials reflect a wide range of inhumation practices. The newly discovered flower linings were found in four Natufian graves at the burial site of Raqefet Cave, Mt. Carmel, Israel. Large identified plant impressions in the graves include stems of sage and other Lamiaceae (Labiatae; mint family) or Scrophulariaceae (figwort family) species; accompanied by a plethora of phytoliths, they provide the earliest direct evidence now known for such preparation and decoration of graves. Some of the plant species attest to spring burials with a strong emphasis on colorful and aromatic flowers. Cave floor chiseling to accommodate the desired grave location and depth is also evident at the site. Thus, grave preparation was a sophisticated planned process, embedded with social and spiritual meanings reflecting a complex preagricultural society undergoing profound changes at the end of the Pleistocene.

Perceived Stress and an Elaborated Structural Model of Adult Student Persistence: An Examination of Financial Aid, Financial Satisfaction, Intent To Persist and Persistence.

ERIC Educational Resources Information Center

Sandler, Martin E.

Researchers used cross-sectional survey research to reexamine the problem of adult persistence within undergraduate degree programs. They identified a variable--perceived stress--that permitted a richer explanation of the process of student persistence. A model was presented that examined the attitudinal and behavioral impacts of unmet need,…

Using Benchmarking To Strengthen the Assessment of Persistence.

PubMed

McLachlan, Michael S; Zou, Hongyan; Gouin, Todd

2017-01-03

Chemical persistence is a key property for assessing chemical risk and chemical hazard. Current methods for evaluating persistence are based on laboratory tests. The relationship between the laboratory based estimates and persistence in the environment is often unclear, in which case the current methods for evaluating persistence can be questioned. Chemical benchmarking opens new possibilities to measure persistence in the field. In this paper we explore how the benchmarking approach can be applied in both the laboratory and the field to deepen our understanding of chemical persistence in the environment and create a firmer scientific basis for laboratory to field extrapolation of persistence test results.

K-ras Mutations as the Earliest Driving Force in a Subset of Colorectal Carcinomas

PubMed Central

MARGETIS, NIKOLAOS; KOULOUKOUSSA, MYRSINI; PAVLOU, KYRIAKI; VRAKAS, SPYRIDON; MARIOLIS-SAPSAKOS, THEODOROS

2017-01-01

K-ras oncogene is a key factor in colorectal cancer. Based on published and our data we propose that K-ras could be the oncogene responsible for the inactivation of the tumor-suppressor gene APC, currently considered as the initial step in colorectal tumorigenesis. K-ras fulfills the criteria of the oncogene-induced DNA damage model, as it can provoke well- established causes for inactivating tumor-suppressors, i.e. DNA double-strand breaks (causing allele deletion) and ROS production (responsible for point mutation). The model we propose is a variation of the currently existing model and hypothesizes that, in a subgroup of colorectal carcinomas, K-ras mutation may precede APC inactivation, representing the earliest driving force and, probably, an early biomarker of colorectal carcinogenesis. This observation is clinically useful, since it may modify the preventive colorectal cancer strategy, restricting numerically patients undergoing colonoscopies to those bearing K-ras mutation in their colorectum, either in benign polyps or the normal accompanying mucosa. PMID:28652417

Earliest record of the invasive Foraminifera Trochammina hadai in San Francisco Bay, California, USA

USGS Publications Warehouse

McGann, Mary

2014-01-01

In 1995, Trochammina hadai, a benthic Foraminifera prevalent in Japanese estuaries, was found in San Francisco Bay, California, USA. Subsequent field investigations determined that the species was also present in nearly all of the major ports and estuaries along the western United States. Because of its widespread colonization, it is of interest to determine when T. hadai first appeared as an invasive in the coastal regions of the North Pacific. In San Francisco Bay, the species was not found in 404 surface samples collected between 1930 and 1981. In 1983, however, a grab sediment sample from one of four sites in the southern portion of the bay contained T. hadai. This site was the most northern of the four and contained 12 specimens of the invasive, comprising 1.5% of the assemblage. This is the earliest appearance on record of T. hadai in San Francisco Bay.

Earliest land plants created modern levels of atmospheric oxygen

PubMed Central

Lenton, Timothy M.; Dahl, Tais W.; Daines, Stuart J.; Mills, Benjamin J. W.; Ozaki, Kazumi; Saltzman, Matthew R.; Porada, Philipp

2016-01-01

The progressive oxygenation of the Earth’s atmosphere was pivotal to the evolution of life, but the puzzle of when and how atmospheric oxygen (O2) first approached modern levels (∼21%) remains unresolved. Redox proxy data indicate the deep oceans were oxygenated during 435–392 Ma, and the appearance of fossil charcoal indicates O2 >15–17% by 420–400 Ma. However, existing models have failed to predict oxygenation at this time. Here we show that the earliest plants, which colonized the land surface from ∼470 Ma onward, were responsible for this mid-Paleozoic oxygenation event, through greatly increasing global organic carbon burial—the net long-term source of O2. We use a trait-based ecophysiological model to predict that cryptogamic vegetation cover could have achieved ∼30% of today’s global terrestrial net primary productivity by ∼445 Ma. Data from modern bryophytes suggests this plentiful early plant material had a much higher molar C:P ratio (∼2,000) than marine biomass (∼100), such that a given weathering flux of phosphorus could support more organic carbon burial. Furthermore, recent experiments suggest that early plants selectively increased the flux of phosphorus (relative to alkalinity) weathered from rocks. Combining these effects in a model of long-term biogeochemical cycling, we reproduce a sustained +2‰ increase in the carbonate carbon isotope (δ13C) record by ∼445 Ma, and predict a corresponding rise in O2 to present levels by 420–400 Ma, consistent with geochemical data. This oxygen rise represents a permanent shift in regulatory regime to one where fire-mediated negative feedbacks stabilize high O2 levels. PMID:27528678

The earliest mantle fabrics formed during subduction zone infancy

NASA Astrophysics Data System (ADS)

Harigane, Y.; Michibayashi, K.; Morishita, T.; Tani, K.; Dick, H. J.; Ishizuka, O.

2013-12-01

Harzburgites obtained from the oldest crust-mantle section in the Philippine Sea plate along the landward slope of the southern Izu-Ogasawara Trench in Izu-Bonin-Mariana arc, that explored by Dive 7K417 of the ROV Kaiko 7000II during R/V Kairei cruise KR08-07, and Dredge 31 of R/V Hakuho-Maru cruise KH07-02, operated by the Japan Agency for Marine-Earth Science and Technology. Harzburgites preserve mantle fabrics formed during the infancy of the subduction zone; that is during the initial stages of Pacific plate subduction beneath the Philippine Sea plate. The main constituent minerals of harzburgites are olivine (15.6%), orthopyroxene (Opx; 13.1%) and spinel (0.5%), along with serpentine (70.8%) as a secondary mineral. Microstructure shows inequigranular interlobate (or protogranular) textures. There is no secondary deformation such as porphyroclastic or fine-grained textures. The secondary serpentine shows undeformed mesh texture in the harzburgites. Harzburgites have crystal preferred orientation patterns in olivine (001)[100] and Opx (100)[001]. The mineral chemistry in harzburgites have high olivine forsterite (90.6-92.1 mol.%) and NiO (~0.4 wt%) contents, low Opx Al2O3 (<~1.5 wt%) and Na2O (<0.03 wt%), and high spinel Cr# (65-67). This has the characteristics of residual peridotites, whereas the dunites, obtained from the same location as the harzburgites, provide evidence for the earliest stages of arc volcanism during the inception of subduction. Therefore, we propose that the (001)[100] olivine patterns began forming in immature fore-arc mantle with an increase in slab-derived hydrous fluids during the initial stages of subduction in in situ oceanic island arc.

Earliest example of a giant monitor lizard (Varanus, Varanidae, Squamata).

PubMed

Conrad, Jack L; Balcarcel, Ana M; Mehling, Carl M

2012-01-01

Varanidae is a clade of tiny (<20 mm pre-caudal length [PCL]) to giant (>600 mm PCL) lizards first appearing in the Cretaceous. True monitor lizards (Varanus) are known from diagnostic remains beginning in the early Miocene (Varanus rusingensis), although extremely fragmentary remains have been suggested as indicating earlier Varanus. The paleobiogeographic history of Varanus and timing for origin of its gigantism remain uncertain. A new Varanus from the Mytilini Formation (Turolian, Miocene) of Samos, Greece is described. The holotype consists of a partial skull roof, right side of a braincase, partial posterior mandible, fragment of clavicle, and parts of six vertebrae. A cladistic analysis including 83 taxa coded for 5733 molecular and 489 morphological characters (71 previously unincluded) demonstrates that the new fossil is a nested member of an otherwise exclusively East Asian Varanus clade. The new species is the earliest-known giant (>600 mm PCL) terrestrial lizard. Importantly, this species co-existed with a diverse continental mammalian fauna. The new monitor is larger (longer) than 99% of known fossil and living lizards. Varanus includes, by far, the largest limbed squamates today. The only extant non-snake squamates that approach monitors in maximum size are the glass-snake Pseudopus and the worm-lizard Amphisbaena. Mosasauroids were larger, but exclusively marine, and occurred only during the Late Cretaceous. Large, extant, non-Varanus, lizards are limbless and/or largely isolated from mammalian competitors. By contrast, our new Varanus achieved gigantism in a continental environment populated by diverse eutherian mammal competitors.

The earliest Lunar Magma Ocean differentiation recorded in Fe isotopes

NASA Astrophysics Data System (ADS)

Wang, Kun; Jacobsen, Stein B.; Sedaghatpour, Fatemeh; Chen, Heng; Korotev, Randy L.

2015-11-01

Recent high-precision isotopic measurements show that the isotopic similarity of Earth and Moon is unique among all known planetary bodies in our Solar System. These observations provide fundamental constraints on the origin of Earth-Moon system, likely a catastrophic Giant Impact event. However, in contrast to the isotopic composition of many elements (e.g., O, Mg, Si, K, Ti, Cr, and W), the Fe isotopic compositions of all lunar samples are significantly different from those of the bulk silicate Earth. Such a global Fe isotopic difference between the Moon and Earth provides an important constraint on the lunar formation - such as the amount of Fe evaporation as a result of a Giant Impact origin of the Moon. Here, we show through high-precision Fe isotopic measurements of one of the oldest lunar rocks (4.51 ± 0.10 Gyr dunite 72 415), compared with Fe isotope results of other lunar samples from the Apollo program, and lunar meteorites, that the lunar dunite is enriched in light Fe isotopes, complementing the heavy Fe isotope enrichment in other lunar samples. Thus, the earliest olivine accumulation in the Lunar Magma Ocean may have been enriched in light Fe isotopes. This new observation allows the Fe isotopic composition of the bulk silicate Moon to be identical to that of the bulk silicate Earth, by balancing light Fe in the deep Moon with heavy Fe in the shallow Moon rather than the Moon having a heavier Fe isotope composition than Earth as a result of Giant Impact vaporization.

Earliest Example of a Giant Monitor Lizard (Varanus, Varanidae, Squamata)

PubMed Central

Conrad, Jack L.; Balcarcel, Ana M.; Mehling, Carl M.

2012-01-01

Background Varanidae is a clade of tiny (<20 mm pre-caudal length [PCL]) to giant (>600 mm PCL) lizards first appearing in the Cretaceous. True monitor lizards (Varanus) are known from diagnostic remains beginning in the early Miocene (Varanus rusingensis), although extremely fragmentary remains have been suggested as indicating earlier Varanus. The paleobiogeographic history of Varanus and timing for origin of its gigantism remain uncertain. Methodology/Principal Findings A new Varanus from the Mytilini Formation (Turolian, Miocene) of Samos, Greece is described. The holotype consists of a partial skull roof, right side of a braincase, partial posterior mandible, fragment of clavicle, and parts of six vertebrae. A cladistic analysis including 83 taxa coded for 5733 molecular and 489 morphological characters (71 previously unincluded) demonstrates that the new fossil is a nested member of an otherwise exclusively East Asian Varanus clade. The new species is the earliest-known giant (>600 mm PCL) terrestrial lizard. Importantly, this species co-existed with a diverse continental mammalian fauna. Conclusions/Significance The new monitor is larger (longer) than 99% of known fossil and living lizards. Varanus includes, by far, the largest limbed squamates today. The only extant non-snake squamates that approach monitors in maximum size are the glass-snake Pseudopus and the worm-lizard Amphisbaena. Mosasauroids were larger, but exclusively marine, and occurred only during the Late Cretaceous. Large, extant, non-Varanus, lizards are limbless and/or largely isolated from mammalian competitors. By contrast, our new Varanus achieved gigantism in a continental environment populated by diverse eutherian mammal competitors. PMID:22900001

Technological variation in the earliest Oldowan from Gona, Afar, Ethiopia.

PubMed

Stout, Dietrich; Semaw, Sileshi; Rogers, Michael J; Cauche, Dominique

2010-06-01

Inter-site technological variation in the archaeological record is one of the richest potential sources of information about Plio-Pleistocene hominid behavior and evolution. However, appropriate methods for describing and comparing Oldowan assemblages have yet to be agreed upon, and interpretation of the early record remains highly controversial. Particularly salient is disagreement over whether the Oldowan is a single technological phenomenon or is more accurately divided into multiple regional and/or chronological traditions, perhaps including a less developed Pre-Oldowan phase in the late Pliocene. Some of this disagreement reflects theoretical and methodological differences between research traditions and some is more directly evidential. Here we present a framework for describing and interpreting Oldowan variation and apply it to three Pliocene assemblages (EG-10, EG-12, and OGS-7) from Gona, all dated to c. 2.6 million years (Ma). Results indicate proficient knapping and a full range of Oldowan reduction strategies in these earliest known occurrences, consistent with the idea of an Oldowan "technological stasis" from 2.6-1.6 Ma. Patterns of variation in raw material selection and predominant reduction strategy at each site clearly indicate the importance of cultural transmission in the Oldowan, but confounding ecological and economic variation continue to render interpretation in terms of multiple tool making traditions or species inappropriate. We propose that cultural transmission and ecological adaptation should be recognized as complementary, rather than mutually exclusive, mechanisms in future attempts to explain Oldowan technological variation. Copyright 2010 Elsevier Ltd. All rights reserved.

Drought Persistence Errors in Global Climate Models

NASA Astrophysics Data System (ADS)

Moon, H.; Gudmundsson, L.; Seneviratne, S. I.

2018-04-01

The persistence of drought events largely determines the severity of socioeconomic and ecological impacts, but the capability of current global climate models (GCMs) to simulate such events is subject to large uncertainties. In this study, the representation of drought persistence in GCMs is assessed by comparing state-of-the-art GCM model simulations to observation-based data sets. For doing so, we consider dry-to-dry transition probabilities at monthly and annual scales as estimates for drought persistence, where a dry status is defined as negative precipitation anomaly. Though there is a substantial spread in the drought persistence bias, most of the simulations show systematic underestimation of drought persistence at global scale. Subsequently, we analyzed to which degree (i) inaccurate observations, (ii) differences among models, (iii) internal climate variability, and (iv) uncertainty of the employed statistical methods contribute to the spread in drought persistence errors using an analysis of variance approach. The results show that at monthly scale, model uncertainty and observational uncertainty dominate, while the contribution from internal variability is small in most cases. At annual scale, the spread of the drought persistence error is dominated by the statistical estimation error of drought persistence, indicating that the partitioning of the error is impaired by the limited number of considered time steps. These findings reveal systematic errors in the representation of drought persistence in current GCMs and suggest directions for further model improvement.

Volusia Blue Spring - A Hydrological Treasure

USGS Publications Warehouse

German, Edward R.

2008-01-01

Springs are natural openings in the ground through which water beneath the surface discharges into hydrologic features such as lakes, rivers, or the ocean. The beautiful springs and spring rivers are among Florida's most valued natural resources; their gemlike refreshing waters have been a focal point of life from prehistoric times to the present (2008). The steady flow of freshwater at a nearly constant water temperature attracted animals now long absent from Florida's landscape. Fossil remains and human artifacts, discovered by divers from many spring runs, attest to the importance of springs to the State's earliest inhabitants. Explorers of Florida, from Ponce de Leon to John and William Bartram and others, often mentioned the springs that were scattered across central and northern Florida. As colonists and settlers began to inhabit Florida, springs continued to be the focus of human activity, becoming sites of missions, towns, and steamboat landings.

Visual persistence and cinema?

PubMed

Galifret, Yves

2006-01-01

In Faraday and Plateau's days, both apparent motion and the fusion of intermittent lights, two phenomena that are hardly connected, were explained by retinal persistence. The works of Exner and of the 'Gestalt' psychologists, as well as the modern works on 'sampled' motion and smooth motion, disregarded retinal persistence. One tried, originally, to measure this persistence using intermittent stimulation, but under the pressure of practical concern, what was established in 1902 was the logarithmic relation between fusion frequency and the intensity of the stimulation. One had to wait until the 1950s for the use of harmonic analysis to finally allow a renewal in which many problems that, for decades, had only given rise to discussions that led nowhere and to groundless assertions, were correctly stated and easily solved. To cite this article: Y. Galifret, C. R. Biologies 329 (2006).

Earliest domestication of common millet (Panicum miliaceum) in East Asia extended to 10,000 years ago

PubMed Central

Lu, Houyuan; Zhang, Jianping; Liu, Kam-biu; Wu, Naiqin; Li, Yumei; Zhou, Kunshu; Ye, Maolin; Zhang, Tianyu; Zhang, Haijiang; Yang, Xiaoyan; Shen, Licheng; Xu, Deke; Li, Quan

2009-01-01

The origin of millet from Neolithic China has generally been accepted, but it remains unknown whether common millet (Panicum miliaceum) or foxtail millet (Setaria italica) was the first species domesticated. Nor do we know the timing of their domestication and their routes of dispersal. Here, we report the discovery of husk phytoliths and biomolecular components identifiable solely as common millet from newly excavated storage pits at the Neolithic Cishan site, China, dated to between ca. 10,300 and ca. 8,700 calibrated years before present (cal yr BP). After ca. 8,700 cal yr BP, the grain crops began to contain a small quantity of foxtail millet. Our research reveals that the common millet was the earliest dry farming crop in East Asia, which is probably attributed to its excellent resistance to drought. PMID:19383791

Precise U-Pb Zircon Constraints on the Earliest Magmatic History of the Carolina Terrane.

PubMed

Wortman; Samson; Hibbard

2000-05-01

The early magmatic and tectonic history of the Carolina terrane and its possible affinities with other Neoproterozoic circum-Atlantic arc terranes have been poorly understood, in large part because of a lack of reliable geochronological data. Precise U-Pb zircon dates for the Virgilina sequence, the oldest exposed part, constrain the timing of the earliest known stage of magmatism in the terrane and of the Virgilina orogeny. A flow-banded rhyolite sampled from a metavolcanic sequence near Chapel Hill, North Carolina, yielded a U-Pb zircon date of 632.9 +2.6/-1.9 Ma. A granitic unit of the Chapel Hill pluton, which intrudes the metavolcanic sequence, yielded a nearly identical U-Pb zircon date of 633 +2/-1.5 Ma, interpreted as its crystallization age. A felsic gneiss and a dacitic tuff from the Hyco Formation yielded U-Pb zircon dates of 619.9 +4.5/-3 Ma and 615.7 +3.7/-1.9 Ma, respectively. Diorite and granite of the Flat River complex have indistinguishable U-Pb upper-intercept dates of 613.9 +1.6/-1.5 Ma and 613.4 +2.8/-2 Ma. The Osmond biotite-granite gneiss, which intruded the Hyco Formation before the Virgilina orogeny, crystallized at 612.4 +5.2/-1.7 Ma. Granite of the Roxboro pluton, an intrusion that postdated the Virgilina orogeny, yielded a U-Pb upper intercept date of 546.5 +3.0/-2.4 Ma, interpreted as the time of its crystallization. These new dates both provide the first reliable estimates of the age of the Virgilina sequence and document that the earliest known stage of magmatism in the Carolina terrane had begun by 633 +2/-1.5 Ma and continued at least until 612.4 +5.2/-1.7 Ma, an interval of approximately 25 m.yr. Timing of the Virgilina orogeny is bracketed between 612.4 +5.2/-1.7 Ma and 586+/-10 Ma (reported age of the upper Uwharrie Formation). The U-Pb systematics of all units studied in the Virgilina sequence are simple and lack any evidence of an older xenocrystic zircon component, which would indicate the presence of a continental

Different aspects of virus persistence (review).

PubMed

Barnabishvili, N; Topuria, T; Gamtsemlidze, P; Topuria, M

2012-05-01

The article reviews different aspects of virus persistence in human organism. Persistence is a capability acquired and strengthened in the process of evolution of many viruses that is the means of maintenance of species. Viruses of measles, poliomyelitis, mite-like encephalitis, B and C hepatitis, herpes, retro and HIV viruses persist in human organism. Persistence is used by various viruses at various levels; they have different adaptive power and no different pathologic output. But in any case, the necessary condition is that virus should escape from elimination reactions of immune control system. At the same time, the important thing is not to save free virus but to save infected cell. While discussing long-term viral persistence, it is impossible to mark off distinctly the importance of biological participation of macroorganism and provoker in this process. The output of the relationship with infect cell is conditioned on the one hand by permissiveness of cell system, on the other hand by strain pathogen city. The details of attenuation mechanisms of microorganism's different reactions in cases of illness with the same strain are not known well yet. Although, it is clear that in chronic persistence the leading role still has immune system disbalance. In disbalance genesis of immunological equilibration virus-induced changes of immunocompetent cells are high.

Predicting persistence to antidepressant treatment in administrative claims data: Considering the influence of refill delays and prior persistence on other medications

PubMed Central

Bushnell, Greta A; Stürmer, Til; White, Alice; Pate, Virginia; Swanson, Sonja A; Azrael, Deborah; Miller, Matthew

2016-01-01

Background Many patients with major depressive disorder (MDD) who begin antidepressant treatment discontinue use before for six months, the recommended minimum treatment length. This study sought to identify predictors of six-month antidepressant persistence including predictors utilizing patients’ electronic prescription records. Methods Commercially insured children (3–17 years) and adults (18–64 years) with MDD who initiated antidepressant treatment, 1/1/2003–2/28/2010, were assessed for six-month persistence (based on prescriptions’ days supply, allowing a 30-day grace period). Antidepressant persistence prediction models were developed separately for children and adults. Two additional measures, days without medication between the first and second antidepressant fill (children and adults) and prior persistence on other medications (adults only), were added to the models, concordance (c) statistics were compared and risk reclassification evaluated. Results Among children (n=8,837 children) and adults (n=47,495) with MDD, six-month antidepressant persistence was low and varied by age (37%, 18–24 years to 52%, 3–12 and 50–64 years, respectively). Independent baseline predictors of persistence were identified, with model c-statistics: children=0.582, adults=0.584. Patients with more days without medication between fills were less likely to be persistent (10–30 vs. 0 days, children: RR=0.72, adults: RR=0.74), as were adults not previously persistent to other medications (RR=0.73). Limitations The definition of 6-month persistence is dependent on correct days supply values and the grace period utilized; potential predictors were limited to measures available in claims data. Conclusions Six-month antidepressant persistence was low and overall prediction of persistence was poor; however, days without medication between fills and prior persistence on other medications marginally improved the ability to predict antidepressant persistence. PMID:26921866

Persistent hyperplastic tunica vasculosa lentis and persistent hyperplastic primary vitreous in transgenic line TgN3261Rpw.

PubMed

Colitz, C M; Malarkey, D E; Woychik, R P; Wilkinson, J E

2000-09-01

Persistent hyperplastic tunica vasculosa lentis and persistent hyperplastic primary vitreous are congenital ocular anomalies that can lead to cataract formation. A line of insertional mutant mice, TgN3261Rpw, generated at the Oak Ridge National Laboratory in a large-scale insertional mutagenesis program was found to have a low incidence (8/243; 3.29%) of multiple developmental ocular abnormalities. The ocular abnormalities include persistent hyperplastic primary vitreous, persistent hyperplastic tunica vasculosa lentis, failure of cleavage of the anterior segment, retrolental fibrovascular membrane, posterior polar cataract, and detached retina. This transgenic mouse line provides an ontogenetic model because of the high degree of similarity of this entity in humans, dogs, and mice.

A PILOT STUDY OF CHILDREN'S TOTAL EXPOSURE TO PERSISTENT PESTICIDES AND OTHER PERSISTENT ORGANIC POLLUTANTS (CTEPP)

EPA Science Inventory

The Pilot Study of Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) investigated the aggregate exposures of 257 preschool children and their primary adult caregivers to pollutants commonly detected in their everyday environments. ...

The Extraction of Information From Visual Persistence

ERIC Educational Resources Information Center

Erwin, Donald E.

1976-01-01

This research sought to distinguish among three concepts of visual persistence by substituting the physical presence of the target stimulus while simultaneously inhibiting the formation of a persisting representation. Reportability of information about the stimuli was compared to a condition in which visual persistence was allowed to fully develop…

Exclusive and persistent use of the entry coreceptor CXCR4 by human immunodeficiency virus type 1 from a subject homozygous for CCR5 delta32.

PubMed

Michael, N L; Nelson, J A; KewalRamani, V N; Chang, G; O'Brien, S J; Mascola, J R; Volsky, B; Louder, M; White, G C; Littman, D R; Swanstrom, R; O'Brien, T R

1998-07-01

Individuals who are homozygous for the 32-bp deletion in the gene coding for the chemokine receptor and major human immunodeficiency virus type 1 (HIV-1) coreceptor CCR5 (CCR5 -/-) lack functional cell surface CCR5 molecules and are relatively resistant to HIV-1 infection. HIV-1 infection in CCR5 -/- individuals, although rare, has been increasingly documented. We now report that the viral quasispecies from one such individual throughout disease is homogenous, T cell line tropic, and phenotypically syncytium inducing (SI); exclusively uses CXCR4; and replicates well in CCR5 -/- primary T cells. The recently discovered coreceptors BOB and Bonzo are not used. Although early and persistent SI variants have been described in longitudinal studies, this is the first demonstration of exclusive and persistent CXCR4 usage. With the caveat that the earliest viruses available from this subject were from approximately 4 years following primary infection, these data suggest that HIV-1 infection can be mediated and persistently maintained by viruses which exclusively utilize CXCR4. The lack of evolution toward the available minor coreceptors in this subject underscores the dominant biological roles of the major coreceptors CCR5 and CXCR4. This and two similar subjects (R. Biti, R. Ffrench, J. Young, B. Bennetts, G. Stewart, and T. Liang, Nat. Med. 3:252-253, 1997; I. Theodoreu, L. Meyer, M. Magierowska, C. Katlama, and C. Rouzioux, Lancet 349:1219-1220, 1997) showed relatively rapid CD4+ T-cell declines despite average or low initial viral RNA load. Since viruses which use CXCR4 exclusively cannot infect macrophages, these data have implications for the relative infection of the T-cell compartment versus the macrophage compartment in vivo and for the development of CCR5-based therapeutics.

Persistence. Snapshot Report, Fall 2011

ERIC Educational Resources Information Center

National Student Clearinghouse, 2011

2011-01-01

Today's college student is not your '60s drop-out. In 2010, college students tended to stay enrolled (i.e., persist), even if it was in a different school, according to the National Student Clearinghouse Research Center. For a student enrolled in the fall, persistence is defined as either continued enrollment during the next term after the fall or…

Exploring Non-Traditional Adult Undergraduate Student Persistence and Non-Persistence in Higher Education: A Stress and Coping Model Approach

ERIC Educational Resources Information Center

Maroney, Barbara R.

2010-01-01

This study explores persistence and non-persistence among adult undergraduate students with particular focus on these students' lives, their stressors, their coping resources including academic supports, and their styles of coping. The study approaches the issue of non-persistence not as a personal failure but rather as a consequence of multiple…

Opportunistic Feeding Strategy for the Earliest Old World Hypsodont Equids: Evidence from Stable Isotope and Dental Wear Proxies

PubMed Central

Tütken, Thomas; Kaiser, Thomas M.; Vennemann, Torsten; Merceron, Gildas

2013-01-01

Background The equid Hippotherium primigenium, with moderately hypsodont cheek teeth, rapidly dispersed through Eurasia in the early late Miocene. This dispersal of hipparions into the Old World represents a major faunal event during the Neogene. The reasons for this fast dispersal of H. primigenium within Europe are still unclear. Based on its hypsodonty, a high specialization in grazing is assumed although the feeding ecology of the earliest European hipparionines within a pure C3 plant ecosystem remains to be investigated. Methodology/Principal Findings A multi-proxy approach, combining carbon and oxygen isotopes from enamel as well as dental meso- and microwear analyses of cheek teeth, was used to characterize the diet of the earliest European H. primigenium populations from four early Late Miocene localities in Germany (Eppelsheim, Höwenegg), Switzerland (Charmoille), and France (Soblay). Enamel δ13C values indicate a pure C3 plant diet with small (<1.4‰) seasonal variations for all four H. primigenium populations. Dental wear and carbon isotope compositions are compatible with dietary differences. Except for the Höwenegg hipparionines, dental microwear data indicate a browse-dominated diet. By contrast, the tooth mesowear patterns of all populations range from low to high abrasion suggesting a wide spectrum of food resources. Conclusions/Significance Combined dental wear and stable isotope analysis enables refined palaeodietary reconstructions in C3 ecosystems. Different H. primigenium populations in Europe had a large spectrum of feeding habits with a high browsing component. The combination of specialized phenotypes such as hypsodont cheek teeth with a wide spectrum of diet illustrates a new example of the Liem’s paradox. This dietary flexibility associated with the capability to exploit abrasive food such as grasses probably contributed to the rapid dispersal of hipparionines from North America into Eurasia and the fast replacement of the brachydont

MOOCs and Persistence: Definitions and Predictors

ERIC Educational Resources Information Center

Evans, Brent J.; Baker, Rachel B.

2016-01-01

The chapter argues for redefining the term "persistence" as it relates to MOOCs and considers how different measures produce different results in the research; it closes with a review of research on persistence in MOOCs.

The termites of Early Eocene Cambay amber, with the earliest record of the Termitidae (Isoptera)

PubMed Central

Engel, Michael S.; Grimaldi, David A.; Nascimbene, Paul C.; Singh, Hukam

2011-01-01

Abstract The fauna of termites (Isoptera) preserved in Early Eocene amber from the Cambay Basin (Gujarat, India) are described and figured. Three new genera and four new species are recognized, all of them Neoisoptera – Parastylotermes krishnai Engel & Grimaldi, sp. n. (Stylotermitidae); Prostylotermes kamboja Engel & Grimaldi, gen. et sp. n. (Stylotermitidae?); Zophotermes Engel, gen. n., with Zophotermes ashoki Engel & Singh, sp. n. (Rhinotermitidae: Prorhinotermitinae); and Nanotermes isaacae Engel & Grimaldi, gen. et sp. n. (Termitidae: Termitinae?). Together these species represent the earliest Tertiary records of the Neoisoptera and the oldest definitive record of Termitidae, a family that comprises >75% of the living species of Isoptera. Interestingly, the affinities of the Cambay amber termites are with largely Laurasian lineages, in this regard paralleling relationships seen between the fauna of bees and some flies. Diversity of Neoisoptera in Indian amber may reflect origin of the amber deposit in Dipterocarpaceae forests formed at or near the paleoequator. PMID:22287892

Earliest human occupations at Dmanisi (Georgian Caucasus) dated to 1.85–1.78 Ma

PubMed Central

Ferring, Reid; Oms, Oriol; Agustí, Jordi; Berna, Francesco; Nioradze, Medea; Shelia, Teona; Tappen, Martha; Vekua, Abesalom; Zhvania, David; Lordkipanidze, David

2011-01-01

The early Pleistocene colonization of temperate Eurasia by Homo erectus was not only a significant biogeographic event but also a major evolutionary threshold. Dmanisi's rich collection of hominin fossils, revealing a population that was small-brained with both primitive and derived skeletal traits, has been dated to the earliest Upper Matuyama chron (ca. 1.77 Ma). Here we present archaeological and geologic evidence that push back Dmanisi's first occupations to shortly after 1.85 Ma and document repeated use of the site over the last half of the Olduvai subchron, 1.85–1.78 Ma. These discoveries show that the southern Caucasus was occupied repeatedly before Dmanisi's hominin fossil assemblage accumulated, strengthening the probability that this was part of a core area for the colonization of Eurasia. The secure age for Dmanisi's first occupations reveals that Eurasia was probably occupied before Homo erectus appears in the East African fossil record. PMID:21646521

Persistence. Snapshot™ Report, Spring 2016

ERIC Educational Resources Information Center

National Student Clearinghouse, 2016

2016-01-01

Of all students who started college in fall 2014, 72.1 percent persisted at any U.S. institution in fall 2015, while 60.6 percent were retained at their starting institution. The persistence rate is the percentage of students who return to college at any institution for their second year, while the retention rate is the percentage of students who…

Ichnotaxonomy of the Laetoli trackways: The earliest hominin footprints

NASA Astrophysics Data System (ADS)

Meldrum, D. J.; Lockley, Martin G.; Lucas, Spencer G.; Musiba, Charles

2011-04-01

At 3.6 Ma, the Laetoli Pliocene hominin trackways are the earliest direct evidence of hominin bipedalism. Three decades since their discovery, not only is the question of their attribution still discussed, but marked differences in interpretation concerning the footprints' qualitative features and the inferred nature of the early hominin foot morphology remain. Here, we establish a novel ichnotaxon, Praehominipes laetoliensis, for these tracks and clarify the distinctions of these footprints from those of later hominins, especially modern humans. We also contrast hominin, human, and ape footprints to establish morphological features of these footprints correlated with a midtarsal break versus a stiff longitudinal arch. Original photos, including stereo photographs, and casts of footprints from the 1978 Laetoli excavation, confirm midtarsal flexibility, and repeatedly indicate an associated midfoot pressure ridge. In contrast, the modern human footprint reflects the derived arched-foot architecture, combined with a stiff-legged striding gait. Fossilized footprints of unshod modern human pedestrians in Hawaii and Nicaragua unambiguously illustrate these contrasts. Some points of comparisons with ape footprints are complicated by a variable hallucal position and the distinct manner of ape facultative bipedalism. In contrast to the comparatively rigid platform of the modern human foot, midtarsal flexibility is present in the chimpanzee foot. In ape locomotion, flexion at the transverse tarsal joint, referred to as the "midtarsal break," uncouples the respective functions of the prehensile forefoot and the propulsive hindfoot during grasp-climbing. At some point after the transition to habitual bipedalism, these grasp-climb adaptations, presumed to be present in the last common ancestor of apes and humans, were initially compromised by the loss of divergence of the hallux. An analogous trajectory is evident along an array of increasingly terrestrial extant ape species

PERSISTENT CONTAMINANTS: NEW PRIORITIES, NEW CONCERNS

EPA Science Inventory

The Stockholm Convention on persistent organic pollutants (POPs) was adopted in 2001 to protect human health and the environment from chemicals that are highly toxic, persistent, bioaccumulative, and undergo long range transport. These POPs include 9 pesticides, polychlorin...

Organizing and Typing Persistent Objects Within an Object-Oriented Framework

NASA Technical Reports Server (NTRS)

Madany, Peter W.; Campbell, Roy H.

1991-01-01

Conventional operating systems provide little or no direct support for the services required for an efficient persistent object system implementation. We have built a persistent object scheme using a customization and extension of an object-oriented operating system called Choices. Choices includes a framework for the storage of persistent data that is suited to the construction of both conventional file system and persistent object system. In this paper we describe three areas in which persistent object support differs from file system support: storage organization, storage management, and typing. Persistent object systems must support various sizes of objects efficiently. Customizable containers, which are themselves persistent objects and can be nested, support a wide range of object sizes in Choices. Collections of persistent objects that are accessed as an aggregate and collections of light-weight persistent objects can be clustered in containers that are nested within containers for larger objects. Automated garbage collection schemes are added to storage management and have a major impact on persistent object applications. The Choices persistent object store provides extensible sets of persistent object types. The store contains not only the data for persistent objects but also the names of the classes to which they belong and the code for the operation of the classes. Besides presenting persistent object storage organization, storage management, and typing, this paper discusses how persistent objects are named and used within the Choices persistent data/file system framework.

76 FR 10578 - Combined Notice of Filings # 1

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-25

... Numbers: ER11-2904-000. Applicants: Settlers Trail Wind Farm, LLC. Description: Settlers Trail Wind Farm, LLC submits tariff filing per 35.12: Settlers Trail Wind Farm, LLC, Market-Based Rate Tariff to be... Time on Thursday, March 10, 2011. Docket Numbers: ER11-2905-000. Applicants: Pioneer Trail Wind Farm...

On species persistence-time distributions.

PubMed

Suweis, S; Bertuzzo, E; Mari, L; Rodriguez-Iturbe, I; Maritan, A; Rinaldo, A

2012-06-21

We present new theoretical and empirical results on the probability distributions of species persistence times in natural ecosystems. Persistence times, defined as the timespans occurring between species' colonization and local extinction in a given geographic region, are empirically estimated from local observations of species' presence/absence. A connected sampling problem is presented, generalized and solved analytically. Species persistence is shown to provide a direct connection with key spatial macroecological patterns like species-area and endemics-area relationships. Our empirical analysis pertains to two different ecosystems and taxa: a herbaceous plant community and a estuarine fish database. Despite the substantial differences in ecological interactions and spatial scales, we confirm earlier evidence on the general properties of the scaling of persistence times, including the predicted effects of the structure of the spatial interaction network. The framework tested here allows to investigate directly nature and extent of spatial effects in the context of ecosystem dynamics. The notable coherence between spatial and temporal macroecological patterns, theoretically derived and empirically verified, is suggested to underlie general features of the dynamic evolution of ecosystems. Copyright © 2012 Elsevier Ltd. All rights reserved.

Stage of cancer diagnoses among migrants from the former Soviet Union in comparison to the German population - are diagnoses among migrants delayed?

PubMed

Cho, An Bin; Jaehn, Philipp; Holleczek, Bernd; Becher, Heiko; Winkler, Volker

2018-01-17

In this study, we compared stage at diagnosis, standardized incidence ratio (SIR) and standardized mortality ratio (SMR) of most frequent cancer diagnoses between re-settlers (Aussiedler) from the former Soviet Union and the general population in the Saarland in Germany to assess possible delays in diagnosis of cancer among this migrant group. Lung cancer, colorectal cancer, breast cancer, prostate cancer, malignant melanoma of the skin and stomach cancer diagnoses among a cohort of 18,619 re-settlers living in the Saarland between 1990 and 2009 were identified by the federal state's cancer registry. Vital status was available for the respective time-period and used to calculate SIR and SMR in comparison to the autochthonous population. Tumor stages were condensed into local and advanced stages. Odds ratios (OR) for an advanced tumor stage were modeled in dependence of re-settler-status and relevant covariates by logistic regression. Missing values were addressed in a sensitivity analysis. The influence of duration of stay in Germany on advanced stage diagnosis was analyzed among re-settlers. SIR and SMR of lung and breast cancer were lower among female re-settlers, while SIR and SMR of colorectal and prostate cancer were lower among male re-settlers. SIR and SMR of stomach cancer were elevated among both sexes. Female re-settlers showed an elevated OR for being diagnosed with advanced stage breast cancer. Both male and female re-settlers showed an elevated OR when observing all six sites combined (OR among males 1.47, p = 0.04; OR among females 1.37, p = 0.05). The result of elevated ORs was supported in the sensitivity analysis. Finally, male re-settlers showed a weak association between duration of stay in Germany and reduced risk for advanced stage diagnosis. Re-settlers were more likely to be diagnosed at an advanced tumor stage. These findings are in line with previous research having shown unfavorable health care utilization of re-settlers. Overall

Predicting Acute and Persistent Neuropathy Associated with Oxaliplatin

PubMed Central

Alejandro, Linh; Behrendt, Carolyn E.; Chen, Kim; Openshaw, Harry; Shibata, Stephen

2014-01-01

Objectives We sought to predict oxaliplatin-associated peripheral neuropathy during modified FOLFOX6 (mFOLFOX6) therapy. Methods In a 50% female sample, patients with previously untreated, primary or recurrent colorectal cancer were followed through a first course of mFOLFOX6 with oxaliplatin 85 mg/m2 every 2 weeks. Accounting for correlation among a subject's cycles, logistic regression estimated per-cycle risk of acute (under 14 days) and persistent (14 days or more) neuropathy. Proportional hazards regression predicted time to persistent neuropathy. Results Among mFOLFOX6 recipients (n=50, age 58.9 +10.1 years), 36% received concomitant bevacizumab. Of total cycles, 94.2% (422/448) were evaluable. Most (84%) subjects reported neuropathy at least once: 74% reported acute and 48% reported persistent symptoms. On multivariate analysis, risk factors shared by acute and persistent neuropathy were body-surface area >2.0, acute neuropathy in a past cycle, and lower body weight. In addition, risk of acute neuropathy decreased with age (adjusted for renal function and winter season), while risk of persistent neuropathy increased with cumulative dose of oxaliplatin and persistent neuropathy in a past cycle. Concomitant bevacizumab was not a risk factor when administered in Stage IV disease but was associated with persistent neuropathy when administered experimentally in Stage III. Females had no increased risk of either form of neuropathy. After 3 cycles, weight, body-surface area, and prior acute neuropathy predicted time to persistent neuropathy. Conclusions Routinely available clinical factors predict acute and persistent neuropathy associated with oxaliplatin. When validated, the proposed prognostic score for persistent neuropathy can help clinicians counsel patients about chemotherapy. PMID:22547012

The role of viral persistence in flavivirus biology

PubMed Central

Mlera, Luwanika; Melik, Wessam; Bloom, Marshall E.

2014-01-01

In nature, vector-borne flaviviruses are persistently cycled between either the tick or mosquito vector and small mammals such as rodents, skunks, and swine. These viruses account for considerable human morbidity and mortality worldwide. Increasing and substantial evidence of viral persistence in humans, which includes the isolation of RNA by RT-PCR and infectious virus by culture, continues to be reported. Viral persistence can also be established in vitro in various human, animal, arachnid and insect cell lines in culture. Although some research has focused on the potential roles of defective virus particles, evasion of the immune response through the manipulation of autophagy and/or apoptosis, the precise mechanism of flavivirus persistence is still not well understood. We propose additional research for further understanding of how viral persistence is established in different systems. Avenues for additional studies include determining if the multifunctional flavivirus protein NS5 has a role in viral persistence, the development of relevant animal models of viral persistence as well as investigating the host responses that allow vector borne flavivirus replication without detrimental effects on infected cells. Such studies might shed more light on the viral-host relationships, and could be used to unravel the mechanisms for establishment of persistence. PMID:24737600

CTEPP OVERVIEW: A PILOT STUDY OF CHILDREN'S TOTAL EXPOSURE TO PERSISTENT PESTICIDES AND OTHER PERSISTENT ORGANIC POLLUTANTS

EPA Science Inventory

The research study, "Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants," (CTEPP) is a pilot-scale project involving about 260 children in their everyday surroundings. The objectives of CTEPP are twofold: (1) To measure the agg...

In Vivo Persistence of Human Rhinoviruses in Immunosuppressed Patients

PubMed Central

Engelmann, Ilka; Dewilde, Anny; Lazrek, Mouna; Batteux, Mathilde; Hamissi, Aminati; Yakoub-Agha, Ibrahim; Hober, Didier

2017-01-01

Several species of the genus Enterovirus cause persistent infections in humans. Human rhinovirus (HRV) infections are generally self-limiting but occasionally persistent infections have been described. This study aimed to identify persistent HRV infections and investigate the clinical and virologic characteristics of patients with persistent infections. From January 2012 to March 2015, 3714 respiratory specimens from 2608 patients were tested for respiratory viruses by using a multiplex reverse transcription–polymerase chain reaction. A retrospective study was performed. Patients with at least two specimens positive for HRV/enterovirus taken 45 days or longer apart were identified and the HRV/enteroviruses were typed. Patients with persistent infection were compared to patients with reinfection and patients with cleared infection. Phylogenetic analysis of the viral protein(VP)4/VP2 region was performed. 18 patients with persistent HRV/enterovirus infection were identified. Minimum median duration of persistence was 92 days (range 50–455 days). All but one patients with persistence were immunosuppressed. Immunosuppression and hematologic disorders were more frequent in patients with persistence (n = 18) than in patients with reinfection (n = 33) and with cleared infection (n = 25) (p = 0.003 and p = 0.001, respectively). In conclusion, this retrospective study identified HRV persistence in vivo which occurred mainly in immunosuppressed patients. PMID:28151988

Magnetic Reconnection at the Earliest Stage of Solar Flux Emergence

NASA Astrophysics Data System (ADS)

Tian, Hui; Zhu, Xiaoshuai; Peter, Hardi; Zhao, Jie; Samanta, Tanmoy; Chen, Yajie

2018-02-01

On 2016 September 20, the Interface Region Imaging Spectrograph observed an active region during its earliest emerging phase for almost 7 hr. The Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory observed continuous emergence of small-scale magnetic bipoles with a rate of ∼1016 Mx s‑1. The emergence of magnetic fluxes and interactions between different polarities lead to the frequent occurrence of ultraviolet (UV) bursts, which exhibit as intense transient brightenings in the 1400 Å images. In the meantime, discrete small patches with the same magnetic polarity tend to move together and merge, leading to the enhancement of the magnetic fields and thus the formation of pores (small sunspots) at some locations. The spectra of these UV bursts are characterized by the superposition of several chromospheric absorption lines on the greatly broadened profiles of some emission lines formed at typical transition region temperatures, suggesting heating of the local materials to a few tens of thousands of kelvin in the lower atmosphere by magnetic reconnection. Some bursts reveal blue- and redshifts of ∼100 km s‑1 at neighboring pixels, indicating the spatially resolved bidirectional reconnection outflows. Many such bursts appear to be associated with the cancellation of magnetic fluxes with a rate of the order of ∼1015 Mx s‑1. We also investigate the three-dimensional magnetic field topology through a magnetohydrostatic model and find that a small fraction of the bursts are associated with bald patches (magnetic dips). Finally, we find that almost all bursts are located in regions of large squashing factor at the height of ∼1 Mm, reinforcing our conclusion that these bursts are produced through reconnection in the lower atmosphere.

Differences in Meteorological Conditions between Days with Persistent and Non-Persistent Pollution in Beijing, China

NASA Astrophysics Data System (ADS)

You, Ting; Wu, Renguang; Huang, Gang

2018-02-01

We compared the regional synoptic patterns and local meteorological conditions during persistent and non-persistent pollution events in Beijing using US NCEP-Department of Energy reanalysis outputs and observations from meteorological stations. The analysis focused on the impacts of high-frequency (period < 90 days) variations in meteorological conditions on persistent pollution events (those lasting for at least 3 days). Persistent pollution events tended to occur in association with slow-moving weather systems producing stagnant weather conditions, whereas rapidly moving weather systems caused a dramatic change in the local weather conditions so that the pollution event was short-lived. Although Beijing was under the influence of anomalous southerly winds in all four seasons during pollution events, notable differences were identified in the regional patterns of sea-level pressure and local anomalies in relative humidity among persistent pollution events in different seasons. A region of lower pressure was present to the north of Beijing in spring, fall, and winter, whereas regions of lower and higher pressures were observed northwest and southeast of Beijing, respectively, in summer. The relative humidity near Beijing was higher in fall and winter, but lower in spring and summer. These differences may explain the seasonal dependence of the relationship between air pollution and the local meteorological variables. Our analysis showed that the temperature inversion in the lower troposphere played an important part in the occurrence of air pollution under stagnant weather conditions. Some results from this study are based on a limited number of events and thus require validation using more data.

Measuring persistence: A literature review focusing on methodological issues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolfe, A.K.; Brown, M.A.; Trumble, D.

1995-03-01

This literature review was conducted as part of a larger project to produce a handbook on the measurement of persistence. The past decade has marked the development of the concept of persistence and a growing recognition that the long-term impacts of demand-side management (DSM) programs warrant careful assessment. Although Increasing attention has been paid to the topic of persistence, no clear consensus has emerged either about its definition or about the methods most appropriate for its measurement and analysis. This project strives to fill that gap by reviewing the goals, terminology, and methods of past persistence studies. It was conductedmore » from the perspective of a utility that seeks to acquire demand-side resources and is interested in their long-term durability; it was not conducted from the perspective of the individual consumer. Over 30 persistence studies, articles, and protocols were examined for this report. The review begins by discussing the underpinnings of persistence studies: namely, the definitions of persistence and the purposes of persistence studies. Then. it describes issues relevant to both the collection and analysis of data on the persistence of energy and demand savings. Findings from persistence studies also are summarized. Throughout the review, four studies are used repeatedly to illustrate different methodological and analytical approaches to persistence so that readers can track the data collection. data analysis, and findings of a set of comprehensive studies that represent alternative approaches.« less

DNA-crosslinker cisplatin eradicates bacterial persister cells.

PubMed

Chowdhury, Nityananda; Wood, Thammajun L; Martínez-Vázquez, Mariano; García-Contreras, Rodolfo; Wood, Thomas K

2016-09-01

For all bacteria, nearly every antimicrobial fails since a subpopulation of the bacteria enter a dormant state known as persistence, in which the antimicrobials are rendered ineffective due to the lack of metabolism. This tolerance to antibiotics makes microbial infections the leading cause of death worldwide and makes treating chronic infections, including those of wounds problematic. Here, we show that the FDA-approved anti-cancer drug cisplatin [cis-diamminodichloroplatinum(II)], which mainly forms intra-strand DNA crosslinks, eradicates Escherichia coli K-12 persister cells through a growth-independent mechanism. Additionally, cisplatin is more effective at killing Pseudomonas aeruginosa persister cells than mitomycin C, which forms inter-strand DNA crosslinks, and cisplatin eradicates the persister cells of several pathogens including enterohemorrhagic E. coli, Staphylococcus aureus, and P. aeruginosa. Cisplatin was also highly effective against clinical isolates of S. aureus and P. aeruginosa. Therefore, cisplatin has broad spectrum activity against persister cells. Biotechnol. Bioeng. 2016;113: 1984-1992. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Genetics of Persister Formation in Pseudomonas aeruginosa

DTIC Science & Technology

2012-12-14

RNA endonuclease toxin-anti-toxin modules must be knocked out before there is an observable effect on persister formation (Maisonneuve, Shakespeare et...multidrug tolerance in Escherichia coli." J Bacteriol 186(24): 8172-8180. Maisonneuve, E., L. J. Shakespeare , et al. (2011). "Bacterial persistence by RNA...endonuclease toxin-anti-toxin modules must be knocked out before there is an observable effect on persister formation (Maisonneuve, Shakespeare et al. 2011

Persistence of the North American Monsoon over the last 50,000 years in Arizona, USA

NASA Astrophysics Data System (ADS)

Cole, K. L.; Ironside, K. E.; Cobb, N. S.

2012-12-01

-tropical summer monsoonal convective precipitation. This correlation was supported by the analysis of 41 modern samples from throughout the region. Higher values, similar to modern levels, were recorded during the Allerød Interval and earliest Holocene. Much lower levels were recorded during the Full-glacial Wisconsinan and the Younger Dryas Period. These paleogeograpic records and isotopic analyses are temporally and spatially consistent. They suggest that the climate mechanisms responsible transport of summer moisture into Arizona have persisted at various times during the late Wisconsinan, although the amounts, transport dynamics, and moisture sources may have shifted from time to time.

Fundamental bound on the persistence and capacity of short-term memory stored as graded persistent activity.

PubMed

Koyluoglu, Onur Ozan; Pertzov, Yoni; Manohar, Sanjay; Husain, Masud; Fiete, Ila R

2017-09-07

It is widely believed that persistent neural activity underlies short-term memory. Yet, as we show, the degradation of information stored directly in such networks behaves differently from human short-term memory performance. We build a more general framework where memory is viewed as a problem of passing information through noisy channels whose degradation characteristics resemble those of persistent activity networks. If the brain first encoded the information appropriately before passing the information into such networks, the information can be stored substantially more faithfully. Within this framework, we derive a fundamental lower-bound on recall precision, which declines with storage duration and number of stored items. We show that human performance, though inconsistent with models involving direct (uncoded) storage in persistent activity networks, can be well-fit by the theoretical bound. This finding is consistent with the view that if the brain stores information in patterns of persistent activity, it might use codes that minimize the effects of noise, motivating the search for such codes in the brain.

Fundamental bound on the persistence and capacity of short-term memory stored as graded persistent activity

PubMed Central

Pertzov, Yoni; Manohar, Sanjay; Husain, Masud; Fiete, Ila R

2017-01-01

It is widely believed that persistent neural activity underlies short-term memory. Yet, as we show, the degradation of information stored directly in such networks behaves differently from human short-term memory performance. We build a more general framework where memory is viewed as a problem of passing information through noisy channels whose degradation characteristics resemble those of persistent activity networks. If the brain first encoded the information appropriately before passing the information into such networks, the information can be stored substantially more faithfully. Within this framework, we derive a fundamental lower-bound on recall precision, which declines with storage duration and number of stored items. We show that human performance, though inconsistent with models involving direct (uncoded) storage in persistent activity networks, can be well-fit by the theoretical bound. This finding is consistent with the view that if the brain stores information in patterns of persistent activity, it might use codes that minimize the effects of noise, motivating the search for such codes in the brain. PMID:28879851

Fumarate-Mediated Persistence of Escherichia coli against Antibiotics

PubMed Central

Kim, Jun-Seob; Cho, Da-Hyeong; Heo, Paul; Jung, Suk-Chae; Park, Myungseo; Oh, Eun-Joong; Sung, Jaeyun; Kim, Pan-Jun; Lee, Suk-Chan; Lee, Dae-Hee; Lee, Sarah; Lee, Choong Hwan; Shin, Dongwoo

2016-01-01

Bacterial persisters are a small fraction of quiescent cells that survive in the presence of lethal concentrations of antibiotics. They can regrow to give rise to a new population that has the same vulnerability to the antibiotics as did the parental population. Although formation of bacterial persisters in the presence of various antibiotics has been documented, the molecular mechanisms by which these persisters tolerate the antibiotics are still controversial. We found that amplification of the fumarate reductase operon (FRD) in Escherichia coli led to a higher frequency of persister formation. The persister frequency of E. coli was increased when the cells contained elevated levels of intracellular fumarate. Genetic perturbations of the electron transport chain (ETC), a metabolite supplementation assay, and even the toxin-antitoxin-related hipA7 mutation indicated that surplus fumarate markedly elevated the E. coli persister frequency. An E. coli strain lacking succinate dehydrogenase (SDH), thereby showing a lower intracellular fumarate concentration, was killed ∼1,000-fold more effectively than the wild-type strain in the stationary phase. It appears that SDH and FRD represent a paired system that gives rise to and maintains E. coli persisters by producing and utilizing fumarate, respectively. PMID:26810657

Herbicide Persistence in Seawater Simulation Experiments

PubMed Central

Mercurio, Philip; Mueller, Jochen F.; Eaglesham, Geoff; Flores, Florita; Negri, Andrew P.

2015-01-01

Herbicides are detected year-round in marine waters, including those of the World Heritage listed Great Barrier Reef (GBR). The few previous studies that have investigated herbicide persistence in seawater generally reported half-lives in the order of months, and several studies were too short to detect significant degradation. Here we investigated the persistence of eight herbicides commonly detected in the GBR or its catchments in standard OECD simulation flask experiments, but with the aim to mimic natural conditions similar to those found on the GBR (i.e., relatively low herbicide concentrations, typical temperatures, light and microbial communities). Very little degradation was recorded over the standard 60 d period (Experiment 1) so a second experiment was extended to 365 d. Half-lives of PSII herbicides ametryn, atrazine, diuron, hexazinone and tebuthiuron were consistently greater than a year, indicating high persistence. The detection of atrazine and diuron metabolites and longer persistence in mercuric chloride-treated seawater confirmed that biodegradation contributed to the breakdown of herbicides. The shortest half-life recorded was 88 d for growth-regulating herbicide 2,4-D at 31°C in the dark, while the fatty acid-inhibitor metolachlor exhibited a minimum half-life of 281 d. The presence of moderate light and elevated temperatures affected the persistence of most of the herbicides; however, the scale and direction of the differences were not predictable and were likely due to changes in microbial community composition. The persistence estimates here represent some of the first appropriate data for application in risk assessments for herbicide exposure in tropical marine systems. The long persistence of herbicides identified in the present study helps explain detection of herbicides in nearshore waters of the GBR year round. Little degradation of these herbicides would be expected during the wet season with runoff and associated flood plumes

Herbicide Persistence in Seawater Simulation Experiments.

PubMed

Mercurio, Philip; Mueller, Jochen F; Eaglesham, Geoff; Flores, Florita; Negri, Andrew P

2015-01-01

Herbicides are detected year-round in marine waters, including those of the World Heritage listed Great Barrier Reef (GBR). The few previous studies that have investigated herbicide persistence in seawater generally reported half-lives in the order of months, and several studies were too short to detect significant degradation. Here we investigated the persistence of eight herbicides commonly detected in the GBR or its catchments in standard OECD simulation flask experiments, but with the aim to mimic natural conditions similar to those found on the GBR (i.e., relatively low herbicide concentrations, typical temperatures, light and microbial communities). Very little degradation was recorded over the standard 60 d period (Experiment 1) so a second experiment was extended to 365 d. Half-lives of PSII herbicides ametryn, atrazine, diuron, hexazinone and tebuthiuron were consistently greater than a year, indicating high persistence. The detection of atrazine and diuron metabolites and longer persistence in mercuric chloride-treated seawater confirmed that biodegradation contributed to the breakdown of herbicides. The shortest half-life recorded was 88 d for growth-regulating herbicide 2,4-D at 31°C in the dark, while the fatty acid-inhibitor metolachlor exhibited a minimum half-life of 281 d. The presence of moderate light and elevated temperatures affected the persistence of most of the herbicides; however, the scale and direction of the differences were not predictable and were likely due to changes in microbial community composition. The persistence estimates here represent some of the first appropriate data for application in risk assessments for herbicide exposure in tropical marine systems. The long persistence of herbicides identified in the present study helps explain detection of herbicides in nearshore waters of the GBR year round. Little degradation of these herbicides would be expected during the wet season with runoff and associated flood plumes

The earliest archaeological maize (Zea mays L.) from highland Mexico: New accelerator mass spectrometry dates and their implications

PubMed Central

Piperno, D. R.; Flannery, K. V.

2001-01-01

Accelerator mass spectrometry age determinations of maize cobs (Zea mays L.) from Guilá Naquitz Cave in Oaxaca, Mexico, produced dates of 5,400 carbon-14 years before the present (about 6,250 calendar years ago), making those cobs the oldest in the Americas. Macrofossils and phytoliths characteristic of wild and domesticated Zea fruits are absent from older strata from the site, although Zea pollen has previously been identified from those levels. These results, together with the modern geographical distribution of wild Zea mays, suggest that the cultural practices that led to Zea domestication probably occurred elsewhere in Mexico. Guilá Naquitz Cave has now yielded the earliest macrofossil evidence for the domestication of two major American crop plants, squash (Cucurbita pepo) and maize. PMID:11172082

The earliest archaeological maize (Zea mays L.) from highland Mexico: new accelerator mass spectrometry dates and their implications.

PubMed

Piperno, D R; Flannery, K V

2001-02-13

Accelerator mass spectrometry age determinations of maize cobs (Zea mays L.) from Guilá Naquitz Cave in Oaxaca, Mexico, produced dates of 5,400 carbon-14 years before the present (about 6,250 calendar years ago), making those cobs the oldest in the Americas. Macrofossils and phytoliths characteristic of wild and domesticated Zea fruits are absent from older strata from the site, although Zea pollen has previously been identified from those levels. These results, together with the modern geographical distribution of wild Zea mays, suggest that the cultural practices that led to Zea domestication probably occurred elsewhere in Mexico. Guilá Naquitz Cave has now yielded the earliest macrofossil evidence for the domestication of two major American crop plants, squash (Cucurbita pepo) and maize.

Characterization and Transcriptome Analysis of Acinetobacter baumannii Persister Cells.

PubMed

Alkasir, Rashad; Ma, Yanan; Liu, Fei; Li, Jing; Lv, Na; Xue, Yong; Hu, Yongfei; Zhu, Baoli

2018-06-14

Acinetobacter baumannii is a nonfermenting Gram-negative bacillus. A. baumannii resistance is a significant obstacle to clinical infection treatment. The existence of persister cells (persisters) might represent the reason for therapy failure and relapse, and such cells may be the driving force behind rising resistance rates. In this study, A. baumannii ATCC 19606 was used as a target to explore the essential features of A. baumannii persisters. Antibiotic treatment of A. baumannii cultures at 50-fold the minimum inhibitory concentration resulted in a distinct plateau of surviving drug-tolerant persisters. The sensitive bacteria were lysed with ceftazidime, and the nonreplicating bacteria were isolated for transcriptome analysis using RNA sequencing. We analyzed the transcriptome of A. baumannii persisters and identified significantly differentially expressed genes, as well as their enriched pathways. The results showed that both the GP49 (HigB)/Cro (HigA) and DUF1044/RelB toxin/antitoxin systems were significantly increased during the persister incubation period. In addition, the activities of certain metabolic pathways (such as electron transport, adenosine triphosphate [ATP], and the citrate cycle) decreased sharply after antibiotic treatment and remained low during the persister period, while aromatic compound degradation genes were only upregulated in persisters. These results suggest the involvement of aromatic compound degradation genes in persister formation and maintenance. They further provide the first insight into the mechanism of persister formation in A. baumannii.

Rhinophototherapy in persistent allergic rhinitis.

PubMed

Bella, Zsolt; Kiricsi, Ágnes; Viharosné, Éva Dósa-Rácz; Dallos, Attila; Perényi, Ádám; Kiss, Mária; Koreck, Andrea; Kemény, Lajos; Jóri, József; Rovó, László; Kadocsa, Edit

2017-03-01

Previous published results have revealed that Rhinolight ® intranasal phototherapy is safe and effective in intermittent allergic rhinitis. The present objective was to assess whether phototherapy is also safe and effective in persistent allergic rhinitis. Thirty-four patients with persistent allergic rhinitis were randomized into two groups; twenty-five subjects completed the study. The Rhinolight ® group was treated with a combination of UV-B, UV-A, and high-intensity visible light, while the placebo group received low-intensity visible white light intranasal phototherapy on a total of 13 occasions in 6 weeks. The assessment was based on the diary of symptoms, nasal inspiratory peak flow, quantitative smell threshold, mucociliary transport function, and ICAM-1 expression of the epithelial cells. All nasal symptom scores and nasal inspiratory peak flow measurements improved significantly in the Rhinolight ® group relative to the placebo group and this finding persisted after 4 weeks of follow-up. The smell and mucociliary functions did not change significantly in either group. The number of ICAM-1 positive cells decreased non-significantly in the Rhinolight ® group. No severe side-effects were reported during the treatment period. These results suggest that Rhinolight ® treatment is safe and effective in persistent allergic rhinitis.

Persistent depressive disorder

MedlinePlus

... But, symptoms are not as severe as with major depression . Persistent depressive disorder used to be called dysthymia. ... with PDD will also have an episode of major depression at some point in their lives. Older people ...

Sodium-driven energy conversion for flagellar rotation of the earliest divergent hyperthermophilic bacterium.

PubMed

Takekawa, Norihiro; Nishiyama, Masayoshi; Kaneseki, Tsuyoshi; Kanai, Tamotsu; Atomi, Haruyuki; Kojima, Seiji; Homma, Michio

2015-08-05

Aquifex aeolicus is a hyperthermophilic, hydrogen-oxidizing and carbon-fixing bacterium that can grow at temperatures up to 95 °C. A. aeolicus has an almost complete set of flagellar genes that are conserved in bacteria. Here we observed that A. aeolicus has polar flagellum and can swim with a speed of 90 μm s(-1) at 85 °C. We expressed the A. aeolicus mot genes (motA and motB), which encode the torque generating stator proteins of the flagellar motor, in a corresponding mot nonmotile mutant of Escherichia coli. Its motility was slightly recovered by expression of A. aeolicus MotA and chimeric MotB whose periplasmic region was replaced with that of E. coli. A point mutation in the A. aeolicus MotA cytoplasmic region remarkably enhanced the motility. Using this system in E. coli, we demonstrate that the A. aeolicus motor is driven by Na(+). As motor proteins from hyperthermophilic bacteria represent the earliest motor proteins in evolution, this study strongly suggests that ancient bacteria used Na(+) for energy coupling of the flagellar motor. The Na(+)-driven flagellar genes might have been laterally transferred from early-branched bacteria into late-branched bacteria and the interaction surfaces of the stator and rotor seem not to change in evolution.

Persistence in the WFC3 IR Detector: Intrinsic Variability

NASA Astrophysics Data System (ADS)

Long, Knox S.; Baggett, Sylvia M.

2018-03-01

When the WFC3 IR detector is exposed to a bright source or sources, the sources can appear as afterimages in subsequent exposures, a phenomenon known as persistence. This can affect the science obtained with the IR channel. We have been involved in an effort to predict the brightness of the afterimages so that users can (at a minimum) flag the affected pixels and remove them from their analysis or (even better) subtract the afterimages from their science images to salvage the data. The ability of any model to remove afterimages depends on the degree to which persistence is the same for identical sets of exposures. We investigate possible time variability of persistence in the WFC3 detector using sets of (almost) identical visits comprised of single exposures of Omega Cen followed by a series of darks in which persistence is measured. We analyze 8 data sets, each consisting of two or three identical visits, with stimulus exposures between 49 and 1199 s, and find clear evidence of variability in several of the datasets in darks taken within 1000 s of the stimulus exposure. In most of the datasets, the difference in persistence for saturated pixels in the stimulus exposure is < 0.01 e-/s for darks taken 1000 s after the initial exposure. One of three 274-second visits has significantly more persistence than its two identical visits. Persistence in this visit was higher in all 4 detector quadrants. The persistence in all three visits is well modeled as a power law decay; the visit with higher persistence has a higher power law amplitude. There was nothing unusual about the observing conditions preceding and during each of these visits that can explain the discrepancy in persistence levels. Variation in persistence implies that: (1) Unless and until the source of the variability is understood, any persistence model for the WFC3 array will be limited in its ability to predict persistence in a single observation, and, (2) as a consequence, users should always carefully

Sequence-Dependent Persistence Length of Long DNA

NASA Astrophysics Data System (ADS)

Chuang, Hui-Min; Reifenberger, Jeffrey G.; Cao, Han; Dorfman, Kevin D.

2017-12-01

Using a high-throughput genome-mapping approach, we obtained circa 50 million measurements of the extension of internal human DNA segments in a 41 nm ×41 nm nanochannel. The underlying DNA sequences, obtained by mapping to the reference human genome, are 2.5-393 kilobase pairs long and contain percent GC contents between 32.5% and 60%. Using Odijk's theory for a channel-confined wormlike chain, these data reveal that the DNA persistence length increases by almost 20% as the percent GC content increases. The increased persistence length is rationalized by a model, containing no adjustable parameters, that treats the DNA as a statistical terpolymer with a sequence-dependent intrinsic persistence length and a sequence-independent electrostatic persistence length.

Persistence with treatment for hypertension in actual practice

PubMed Central

Caro, J J; Salas, M; Speckman, J L; Raggio, G; Jackson, J D

1999-01-01

BACKGROUND: Despite the existence of efficacious medications, many patients in actual practice remain with uncontrolled hypertension. Randomized clinical trials, cannot address this issue well given their highly restricted environment. This paper examines persistence with antihypertensive therapy among patients in actual practice. METHODS: Cohort study of patients who received a diagnosis of hypertension and were treated between 1989 and 1994 identified through the Saskatchewan Health databases. Patients with concurrent diagnoses likely to affect initial treatment choice were excluded. The resulting population of 79,591 subjects was grouped into those with established hypertension (52,227 [66%]) and those with newly diagnosed hypertension (27,364 [34%]). The initial antihypertensive prescription, subsequent changes in treatment and persistence with antihypertensive therapy were analysed. RESULTS: Persistence with antihypertensive therapy decreased in the first 6 months after treatment was started and continued to decline over the next 4 years. Of the patients with newly diagnosed hypertension, only 78% persisted with therapy at the end of 1 year, as compared with 97% of the patients with established hypertension (p < 0.001). Among those with newly diagnosed hypertension, older patients were more likely than younger ones to persist, and women were more likely than men to persist (p < 0.001). INTERPRETATION: This analysis of actual practice data indicates that barriers to persistence occur early in the therapeutic course and that achieving successful therapy when treatment is started is important to maintaining long-term persistence. PMID:9934341

Persistent agents in Axelrod's social dynamics model

NASA Astrophysics Data System (ADS)

Reia, Sandro M.; Neves, Ubiraci P. C.

2016-01-01

Axelrod's model of social dynamics has been studied under the effect of external media. Here we study the formation of cultural domains in the model by introducing persistent agents. These are agents whose cultural traits are not allowed to change but may be spread through local neighborhood. In the absence of persistent agents, the system is known to present a transition from a monocultural to a multicultural regime at some critical Q (number of traits). Our results reveal a dependence of critical Q on the occupation probability p of persistent agents and we obtain the phase diagram of the model in the (p,Q) -plane. The critical locus is explained by the competition of two opposite forces named here barrier and bonding effects. Such forces are verified to be caused by non-persistent agents which adhere (adherent agents) to the set of traits of persistent ones. The adherence (concentration of adherent agents) as a function of p is found to decay for constant Q. Furthermore, adherence as a function of Q is found to decay as a power law with constant p.

Long Persistent Light Emitting Diode Indicators

ERIC Educational Resources Information Center

Jia, Dongdong; Ma, Yiwei; Hunter, D. N.

2007-01-01

An undergraduate laboratory was designed for undergraduate students to make long persistent light emitting diode (LED) indicators using phosphors. Blue LEDs, which emit at 465 nm, were characterized and used as an excitation source. Long persistent phosphors, SrAl[subscript 2]O[subscript 4]:Eu[superscript 2+],Dy[superscript 3+] (green) and…

Cutaneous human papillomaviruses persist on healthy skin.

PubMed

Hazard, Kristina; Karlsson, Anna; Andersson, Kristin; Ekberg, Henrik; Dillner, Joakim; Forslund, Ola

2007-01-01

Cutaneous human papillomaviruses (HPVs) are frequently found in healthy skin and have also been implicated in non-melanoma skin cancer. For genital HPV types, a persistent infection with one of the high-risk types is a prerequisite for the development of cervical cancer. However, there is only limited data on whether infections with cutaneous HPV types persist over time. Serial forehead swab samples collected from 63 volunteers (42 healthy individuals and 31 renal transplant recipients (RTRs)), sampled 6.3 years (range: 5.0-7.0 years) apart, were analyzed for HPV using general primer PCR, cloning, and sequencing. Among the healthy individuals, the prevalences of HPV were 69% (29/42) at enrolment and 71% (30/42) at follow-up. Among the individuals positive at baseline, 48% (14/29) had a persistent infection. Among the RTRs, 71% (15/21) were positive for HPV at enrolment and 90% (19/21) at follow-up. A persistent infection was detected in 33% (5/15). In total, HPV was detected in 44 of the samples collected at baseline and the same virus was found at follow-up in 43% (19/44). Persistence was not significantly associated with age, sex, immunosuppressive treatment, history of warts, or genus of HPV. We conclude that cutaneous HPV infections commonly persist over several years on healthy skin.

Treatment of acral persistent papular mucinosis with electrocoagulation.

PubMed

André Jorge, Flávia; Mimura Cortez, Tatiana; Guadalini Mendes, Fabiana; Esther Alencar Marques, Mariângela; Amante Miot, Hélio

2011-01-01

Acral persistent papular mucinosis is a rare localized form of lichen myxedematosus with few case reports and no documented therapeutic options. To report full resolution of acral persistent papular mucinosis after electrocoagulation. Case report of a 51-year-old white female diagnosed with an acral persistent papular mucinosis. The clinical and histopathologic features, treatment provided, and response to treatment are detailed. Acral persistent papular mucinosis presented as multiple asymptomatic normochromic papules on the wrists. Treatment with topical and intralesional steroids was unsatisfactory. Gentle electrocoagulation led to complete resolution of the lesions and negligible scarring. The favorable results remained for 6 months of follow-up, and no new lesions have emerged. Our case of acral persistent papular mucinosis was successfully treated with electrocoagulation and long-lasting, excellent cosmetic results.

Quantification of temperature persistence over the Northern Hemisphere land-area

NASA Astrophysics Data System (ADS)

Pfleiderer, Peter; Coumou, Dim

2017-10-01

Extreme weather events such as heat waves and floods are damaging to society and their contribution to future climate impacts is expected to be large. Such extremes are often related to persistent local weather conditions. Weather persistence is linked to sea surface temperatures, soil-moisture (especially in summer) and large-scale circulation patterns and these factors can alter under past and future climate change. Though persistence is a key characteristic for extreme weather events, to date the climatology and potential changes in persistence have only been poorly documented. Here, we present a systematic analysis of temperature persistence for the northern hemisphere land area. We define persistence as the length of consecutive warm or cold days and use spatial clustering techniques to create regional persistence distributions. We find that persistence is longest in the Arctic and shortest in the mid-latitudes. Parameterizations of the regional persistence distributions show that they are characterized by an exponential decay with a drop in the decay rate for very persistent events, implying that feedback mechanisms are important in prolonging these events. For the mid-latitudes, we find that persistence in summer has increased over the past 60 years. The changes are particularly pronounced for prolonged events suggesting a lengthening in the duration of heat waves.

Tales from the prehistory of Quantum Gravity. Léon Rosenfeld's earliest contributions

NASA Astrophysics Data System (ADS)

Peruzzi, Giulio; Rocci, Alessio

2018-05-01

The main purpose of this paper is to analyse the earliest work of Léon Rosenfeld, one of the pioneers in the search of Quantum Gravity, the supposed theory unifying quantum theory and general relativity. We describe how and why Rosenfeld tried to face this problem in 1927, analysing the role of his mentors: Oskar Klein, Louis de Broglie and Théophile De Donder. Rosenfeld asked himself how quantum mechanics should concretely modify general relativity. In the context of a five-dimensional theory, Rosenfeld tried to construct a unifying framework for the gravitational and electromagnetic interaction and wave mechanics. Using a sort of "general relativistic quantum mechanics" Rosenfeld introduced a wave equation on a curved background. He investigated the metric created by what he called `quantum phenomena', represented by wave functions. Rosenfeld integrated Einstein equations in the weak field limit, with wave functions as source of the gravitational field. The author performed a sort of semi-classical approximation obtaining at the first order the Reissner-Nordström metric. We analyse how Rosenfeld's work is part of the history of Quantum Mechanics, because in his investigation Rosenfeld was guided by Bohr's correspondence principle. Finally we briefly discuss how his contribution is connected with the task of finding out which metric can be generated by a quantum field, a problem that quantum field theory on curved backgrounds will start to address 35 years later.

Tales from the prehistory of Quantum Gravity - Léon Rosenfeld's earliest contributions

NASA Astrophysics Data System (ADS)

Peruzzi, Giulio; Rocci, Alessio

2018-04-01

The main purpose of this paper is to analyse the earliest work of Léon Rosenfeld, one of the pioneers in the search of Quantum Gravity, the supposed theory unifying quantum theory and general relativity. We describe how and why Rosenfeld tried to face this problem in 1927, analysing the role of his mentors: Oskar Klein, Louis de Broglie and Théophile De Donder. Rosenfeld asked himself how quantum mechanics should concretely modify general relativity. In the context of a five-dimensional theory, Rosenfeld tried to construct a unifying framework for the gravitational and electromagnetic interaction and wave mechanics. Using a sort of "general relativistic quantum mechanics" Rosenfeld introduced a wave equation on a curved background. He investigated the metric created by what he called `quantum phenomena', represented by wave functions. Rosenfeld integrated Einstein equations in the weak field limit, with wave functions as source of the gravitational field. The author performed a sort of semi-classical approximation obtaining at the first order the Reissner-Nordström metric. We analyse how Rosenfeld's work is part of the history of Quantum Mechanics, because in his investigation Rosenfeld was guided by Bohr's correspondence principle. Finally we briefly discuss how his contribution is connected with the task of finding out which metric can be generated by a quantum field, a problem that quantum field theory on curved backgrounds will start to address 35 years later.

Mortality, Disenrollment, and Spending Persistence in Medicaid and CHIP.

PubMed

DeLia, Derek

2017-03-01

Research on spending persistence has not focused on Medicaid and the Children's Health Insurance Program (Medicaid/CHIP), which includes a complex and growing population. The objective of the study was to describe patterns of expenditure persistence, mortality, and disenrollment among nondually eligible Medicaid/CHIP enrollees and identify factors predicting these outcomes. The study is based on New Jersey Medicaid/CHIP claims data from 2011 to 2014. Descriptive and multinomial regression methods were used to characterize persistently extreme spenders, defined as those appearing in the top 1% of statewide spending every year, according to demographics, Medicaid/CHIP eligibility, nursing facility residence, patient risk scores, and clinical diagnostic categories measured in 2011. Similar analyses were done for persistently high spenders (ie, always in the top 10% but not always top 1%) as well as decedents, disenrollees, and moderate spenders (ie, at least 1 year outside of the top 10%). Nondually eligible NJ Medicaid/CHIP enrollees in 2011. One fourth of extreme spenders in 2011 remained in that category throughout 2011-2014. Almost all (89.3%) of the persistently extreme spenders were aged, blind, or disabled. Within the aged, blind, or disabled population, the strongest predictors of persistently extreme spending were diagnoses involving developmental disability, HIV/AIDS, central nervous system conditions, psychiatric disorders, type 1 diabetes, and renal conditions. Individuals in nursing facilities and those with very high risk scores were more likely to die or have persistently high spending than to have persistently extreme spending. The study highlights unique features of spending persistence within Medicaid/CHIP and provides methodological contributions to the broader persistence literature.

ANALYTICAL METHODS DEVELOPED FOR THE CHILDREN'S TOTAL EXPOSURES TO PERSISTENT PESTICIDES AND OTHER PERSISTENT ORGANIC POLLUTANTS (CTEPP) STUDY

EPA Science Inventory

The Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) study was designed by the U.S. EPA to collect data on young children's exposures to pesticides and other pollutants in their everyday environments in support of the Food Quality...

Spatial patterns of drought persistence in East China

NASA Astrophysics Data System (ADS)

Meng, L.; Ford, T.

2017-12-01

East China has experienced a number of severe droughts in recent decades. Understanding the characteristics of droughts and their persistence will provide operational guidelines for water resource management and agricultural production. This study uses a logistic regression model to measure the probability of drought occurrence in the current season given the previous season's Standardized Precipitation Index (SPI) and Southern Oscillation Index (SOI) as well as drought persistence. Results reveal large spatial and seasonal variations in the relationship between the previous season's SPI and the drought occurrence probability in a given season. The drought persistence averaged over the entire study area for all the four seasons is approximately 34% with large variations from season to season and from region to region. The East and Northeast regions have the largest summer drought persistence ( 40%) and lowest fall drought persistence ( 28%). The spatial pattern in winter and spring drought persistence is dissimilar with stronger winter and weaker spring drought persistence in the Southwest and Northeast relative to other regions. Logistic regression analysis indicates a stronger negative relationship in summer-to-fall (or between fall drought occurrence and summer SPI) than other inter-season relationships. This study demonstrates that the impact of previous season SPI and SOI on current season drought varies substantially from region to region and from season to season. This study also shows stronger drought persistence in summer than in other seasons. In other words, the probability of fall drought occurrence is closely related to summer moisture conditions in the East China.

Antiphospholipid Antibodies and Recurrent Thrombotic Events: Persistence and Portfolio

PubMed Central

Amory, Colum F.; Levine, Steve R.; Brey, Robin L.; Gebregziabher, Mulugeta; Tuhrim, Stanley; Tilley, Barbara C.; Simpson, Ann-Catherin N.; Sacco, Ralph L.; Mohr, J.P.

2015-01-01

Background There are very limited prospective data on the significance of persistent of antiphospholipid antibodies (aPL) and recurrent thrombo-occlusive events (TOEs). We investigated the prognostic value of (1) two newer aPL assays, (2) an aPL portfolio, and (3) persistent aPL positivity following stroke. Methods 1,770 subjects from the APASS-WARSS study underwent further aPL testing for antibodies to phosphatidylserine (aPS) and β2-glycoprotein-I (anti-β2GPI) from stored sera. Follow-up aPL status was also tested in a subset of subjects. Primary analysis was based on time to any TOE (ischemic stroke, MI, TIA, DVT, PE, or systemic arterial occlusion)/death at 2 years. Cox proportional hazard analyses assessed whether aPL independently related to outcome. Results Persistent anti-β2GPI decreased the time to TOE/death after adjustment for potential confounders (HR=2.86, CI 1.21-6.76, p=0.017). When persistent anti-β2GPI was combined with another persistently positive aPL, time to TOE/death was also reduced (HR=3.79, CI 1.18-12.14, p=0.025). Neither persistent aCL, persistent aPS alone, nor a single positive anti-β2GPI or aPS was associated with decreased time to TOE/death. No single positive aPL, portfolio of baseline aPL, or any persistent aPL increased the rate of TOE/death. Conclusions Rates of TOE/death were not influenced by aPL results at baseline or follow-up. Persistent anti-β2GPI alone and with persistent second aPL were independently associated with decreased time to TOE/death. Persistent aPL, an aPL portfolio, and newer aPL in ischemic stroke patients are not helpful in predicting an increased rate of recurrent TOEs. PMID:26513489

The Spectral Energy Distribution of the Earliest Phases of Massive Star Formation from the Spizter and Herschel Archives

NASA Astrophysics Data System (ADS)

Klein, Randolf; Looney, Leslie; Henning, Thomas; Chakrabarti, Sukanya; Shenoy, Sachin

2015-08-01

Infrared Dark Clouds (IRDCs) are very good candidates for the earliest phases of massive star formation, but can only be found in regions with high infrared background. We have searched for early phases among cold and massive (M>100M⊙) cloud cores by selecting cores from millimeter continuum surveys (Faundez et al. 2004, Sridharan et al. 2005, Klein et al. 2005, Beltran et al. 2006) without associations at short wavelengths. We compared the millimeter continuum peak positions with IR and radio catalogs (2MASS, MSX, IRAS, and NVSS) and excluded cores that had sources associated with the cores' peaks. We compiled a list of 173 cores in over 117 regions that are candidates for very early phases of Massive Star Formation (MSF). Now with the Spitzer and Herschel archives, these cores can be characterized further. The GLIMPSE and MIPSGAL programs alone covered 86 of these regions. The Herschel Archive adds even longer wavelengths. We are compiling this data set to construct the complete spectral energy distribution (SED) in the mid- and far-infrared with good spatial resolution and broad spectral coverage. This allow us to disentangle the complex regions and model the SED of the deeply embedded protostars/clusters.We will be presenting the IR properties of all cores and their embedded source, attempt a characterization, and order the cores in an evolutionary sequence. The resulting properties can be compared to e.g. IRDCs, a class of objects suggested to be the earliest stages of MSF. With the relative large number of cores, we can try to answer questions like: How homogeneous or diverse are our regions in terms of their evolutionary stage? Where do our embedded sources fit in the evolutionary sequence of IRDCs, hot molecular cores, ultra-compact HII regions, etc? How is the MSF shaping the environment and vice versa? Can we extrapolate to the initial conditions of MSF using our evolutionary sequence?

[Persistent diarrhea in the returned traveler].

PubMed

de Saussure, P; Hadengue, A

2006-05-10

Persistent diarrhea in a returned traveler is a frequent presenting complaint and may result from three etiologic groups: persistant infections, non-infectious post-gastroenteritis processes (in particular postinfectious irritable bowel syndrome) and appearance of an unrelated cause of chronic diarrhea. This article reviews the most frequent diseases involved and provides management guidelines for primary care physicians.

Starch granule evidence for the earliest potato use in North America

PubMed Central

Louderback, Lisbeth A.; Pavlik, Bruce M.

2017-01-01

The prehistory of wild potato use, leading to its domestication and diversification, has been well-documented in, and confined to, South America. At least 20 tuber-bearing, wild species of Solanum are known from North and Central America, yet their importance in ancient diets has never been assessed from the archaeological record. Here, we report the earliest evidence of wild potato use in North America at 10,900–10,100 calendar years (cal) B.P. in the form of well-preserved starch granules extracted from ground stone tools at North Creek Shelter, southern Utah. These granules have been identified as those of Solanum jamesii Torr. (Four Corners potato), a tuber-bearing species native to the American Southwest. Identification was based on applying five strictly defined diagnostic characteristics (eccentric hilum, longitudinal fissure, lack of fissure branching, fissure ratio, and maximum granule size) to each of 323 archaeological granules. Of those, nine were definitively assigned to S. jamesii based on possession of all characteristics, and another 61 were either likely or possibly S. jamesii depending on the number of characteristics they possessed. The oldest granules were found in substratum 4k (10,900–10,100 cal B.P.). Younger deposits, dating to ∼6,900 cal B.P., also contained tools with S. jamesii granules, indicating at least 4,000 y of intermittent use. Ethnographic and historical accounts extend the period of use to more than 10,000 y. The question then arises as to whether some S. jamesii populations could have undergone transport, cultivation, and eventual domestication over such a long period of time. PMID:28673982

Non-persistent pesticides removal in constructed wetlands

NASA Astrophysics Data System (ADS)

Tu, Yue; Jiang, Lei; Li, Haixiang

2018-03-01

The heavy use of non-persistent pesticides, resulting in the accumulation of environment and destroy the aquatic environment. This paper presents the research status of using CWs to treat non-persistent pesticides in water. The removal mechanisms are mainly physical deposition, chemical hydrolysis and plant absorption. Analysis of the factors that affect the removal effect are mainly the nature of pesticides, HRT, plants. Some scholars have proposed that secondary products of non-persistent pesticides may be more harmful to the environment, However, the relevant reports are scarce.

Community College Students' Self-Reports of Persistence: Looking beyond Student Satisfaction Ratings of Persisters and Nonpersisters

ERIC Educational Resources Information Center

Cole, Marsha Dee

2013-01-01

Approximately 30% of students who persist to the end of their courses at two-year colleges do not do so with a passing grade, yet research on the educational experiences of these unsuccessful community college persisters remains limited. The purpose of this explanatory mixed-methods study was threefold. First, this study attempted to identify…

Persister eradication: lessons from the world of natural products.

PubMed

Keren, Iris; Mulcahy, Lawrence R; Lewis, Kim

2012-01-01

Persisters are specialized survivor cells that protect bacterial populations from killing by antibiotics. Persisters are dormant phenotypic variants of regular cells rather than mutants. Bactericidal antibiotics kill by corrupting their targets into producing toxic products; tolerance to antibiotics follows when targets are inactive. Transcriptome analysis of isolated persisters points to toxin/antitoxin modules as a principle component of persister formation. Mechanisms of persister formation are redundant, making it difficult to eradicate these cells. In Escherichia coli, toxins RelE and MazF cause dormancy by degrading mRNA; HipA inhibits translation by phosphorylating Ef-Tu; and TisB forms an anion channel in the membrane, leading to a decrease in pmf and ATP levels. Prolonged treatment of chronic infections with antibiotics selects for hip mutants that produce more persister cells. Eradication of tolerant persisters is a serious challenge. Some of the existing antibiotics are capable of killing persisters, pointing to ways of developing therapeutics to treat chronic infections. Mitomycin is a prodrug which is converted into a reactive compound forming adducts with DNA upon entering the cell. Prolonged treatment with aminoglycosides that cause mistranslation leading to misfolded peptides can sterilize a stationary culture of Pseudomonas aeruginosa, a pathogen responsible for chronic, highly tolerant infections of cystic fibrosis patients. Finally, one of the best bactericidal agents is rifampin, an inhibitor of RNA polymerase, and we suggest that it "kills" by preventing persister resuscitation. Copyright © 2012 Elsevier Inc. All rights reserved.

Divergence in sink contributions to population persistence

EPA Science Inventory

Population sinks present unique conservation challenges. The loss of animals in sinks can compromise persistence. Conversely, sinks can bolster population sizes, improving viability. To assess the contribution of sinks to regional persistence, we simulated the removal of sink hab...

Longitudinal risk factors for persistent fatigue in adolescents.

PubMed

Viner, Russell M; Clark, Charlotte; Taylor, Stephanie J C; Bhui, Kam; Klineberg, Emily; Head, Jenny; Booy, Robert; Stansfeld, Stephen A

2008-05-01

To examine whether sedentary behavior, obesity, smoking, and depression are risk factors for persistent fatigue in adolescents. Longitudinal population-based survey. Twenty-eight randomly selected schools in east London, England, in 2001 and 2003. A total of 1880 adolescents (49% male; 81% nonwhite British) aged 11 to 12 years and 13 to 14 years in 2000. Confidential questionnaires completed in class. Persistent fatigue (extreme tiredness twice weekly or more often in the previous month at both surveys), sedentary behavior, physical activity, depressive symptoms, body mass index, and smoking. Severe fatigue was reported in 11% of participants aged 11 to 14 years and 17% of participants aged 13 to 16 years. Eighty-four participants (4%) reported persistent fatigue. Across both surveys, only 3 pupils reported chronic fatigue syndrome. In multivariate logistic regression, risk of persistent fatigue was independently associated with being sedentary for more than 4 hours per day (odds ratio = 1.6; 95% confidence interval, 1.1-2.3; P = .01), being physically active (odds ratio = 1.5; 95% confidence interval, 1.1-2.3; P = .004), and depressive symptoms (odds ratio = 2.0; 95% confidence interval, 1.5-2.7; P < .001) in the first survey, after adjustment for age, sex, and socioeconomic status. Obesity and smoking were not associated with fatigue. Persistent fatigue is common. Being highly sedentary or highly active independently increased the risk of persistent fatigue, suggesting that divergence in either direction from healthy levels of activity increases the risk for persistent fatigue. Mental health is important in the etiology of persistent fatigue. To help define effective preventive strategies, further work is needed on the mechanisms by which these factors contribute to fatigue.

Catheter ablation in patients with persistent atrial fibrillation

PubMed Central

Kirchhof, Paulus; Calkins, Hugh

2017-01-01

Catheter ablation is increasingly offered to patients who suffer from symptoms due to atrial fibrillation (AF), based on a growing body of evidence illustrating its efficacy compared with antiarrhythmic drug therapy. Approximately one-third of AF ablation procedures are currently performed in patients with persistent or long-standing persistent AF. Here, we review the available information to guide catheter ablation in these more chronic forms of AF. We identify the following principles: Our clinical ability to discriminate paroxysmal and persistent AF is limited. Pulmonary vein isolation is a reasonable and effective first approach for catheter ablation of persistent AF. Other ablation strategies are being developed and need to be properly evaluated in controlled, multicentre trials. Treatment of concomitant conditions promoting recurrent AF by life style interventions and medical therapy should be a routine adjunct to catheter ablation of persistent AF. Early rhythm control therapy has a biological rationale and trials evaluating its value are underway. There is a clear need to generate more evidence for the best approach to ablation of persistent AF beyond pulmonary vein isolation in the form of adequately powered controlled multi-centre trials. PMID:27389907

Understanding patient compliance and persistence with osteoporosis therapy.

PubMed

Gold, Deborah T

2011-04-01

Chronic non-terminal diseases, including postmenopausal osteoporosis, are associated with poor treatment compliance and persistence. The longer a patient with osteoporosis complies and persists with treatment, the lower the risk of fracture. Retrospective studies with emphasis on real-world data have led to a greater understanding of the factors affecting medication compliance and persistence, and their association with improved treatment outcomes. However, these data do not contain information about patient choices of medication or patient commitment to particular medication regimens. Patient preferences can affect compliance and persistence behaviours. While recent evidence questions the importance of dosing regimen in patient preferences, other recent data show that medication efficacy and safety remain the most important determinants of patient preference. Informed patient decision making about treatment options, adverse effects and outcomes can have a beneficial impact on medication-taking behaviour. Healthcare professionals play a crucial role in the management of factors associated with poor compliance and persistence with osteoporosis therapies. Education about disease consequences and differences among treatment options, as well as treatment monitoring and positive reinforcement, are crucial to improving medication compliance and persistence in osteoporotic patients.

Petrographic and C & O isotopic characteristics of the earliest stages of aqueous alteration of CM chondrites

NASA Astrophysics Data System (ADS)

Vacher, Lionel G.; Marrocchi, Yves; Villeneuve, Johan; Verdier-Paoletti, Maximilien J.; Gounelle, Matthieu

2017-09-01

CM chondrites form the largest group of hydrated meteorites and span a wide range of alteration states, with the Paris meteorite being the least altered CM described to date. Ca-Carbonates are powerful proxies for the alteration conditions of CMs because they are direct snapshots of the chemical and isotopic compositions of the parent fluids. Here, we report a petrographic and a C isotope and O isotope survey of Ca-carbonates in Paris in order to better characterize the earliest stages of aqueous alteration. Petrographic observations show that Paris contains two distinct populations of Ca-carbonates: Type 1a Ca-carbonates, which are surrounded by rims of tochilinite/cronstedtite intergrowths (TCIs), and new Type 0 Ca-carbonates, which do not exhibit the TCI rims. The TCI rims of Type 1a Ca-carbonates commonly outline euhedral crystal faces, demonstrating that these Ca-carbonates were (i) partially or totally pseudomorphosed by TCI and (ii) precipitated at the earliest stages of aqueous alteration, before Type 0 Ca-carbonates. Isotopic measurements show that Paris' Ca-carbonates have δ13C values that range from 19 to 80‰ (PDB), δ18O values that range from 29 to 41%, and δ17O values that range from 13 to 24‰ (SMOW). According to the δ13C-δ18O values of Paris' Ca-carbonates, we developed a new alteration model that involves (i) the equilibration of a primordial 17,18O-rich water (PW) with 16O-rich anhydrous silicates and (ii) varying contribution of 12C- and 13C-rich soluble organic matter (SOMs). It also suggests that many parameters control the C and O isotopic composition of Ca-carbonates, the principles being the degree of isotopic equilibration between the PW and the anhydrous silicates, the respective contribution of 12C and 13C-rich SOMs as well as the thermal evolution of CM parent bodies. Consequently, we suggest that CM Ca-carbonates could record both positive and negative δ13C-δ18O relationships, but a systematic correspondence is probably absent

New insights into the earliest Quaternary environments in the Central North Sea from 3D seismic

NASA Astrophysics Data System (ADS)

Lamb, Rachel; Huuse, Mads; Stewart, Margaret; Brocklehurst, Simon H.

2014-05-01

In the past the transition between an unconformable surface in the south to a conformable horizon towards the north has made identification and mapping the base-Quaternary in the central North Sea difficult (Sejrup et al 1991; Gatliff et al 1994). However recent integration of biostratigraphy, pollen analysis, paleomagnetism and amino acid analysis in the Dutch and Danish sectors (Rasmussen et al 2005; Kuhlmann et al 2006) has allowed greater confidence in the correlation to the region 3D seismic datasets and thus has allowed the base-Quaternary to be mapped across the entire basin. The base-Quaternary has been mapped using the PGS MegaSurvey dataset from wells in the Danish Sector along the initially unconformable horizon and down the delta front into the more conformable basin giving a high degree of confidence in the horizon pick. The revised base-Quaternary surface reaches a depth of 1248 ms TWT with an elongate basin shape which is significantly deeper than the traditionally mapped surface. Using RMS amplitudes and other seismic attributes the revised base-Quaternary has been investigated along the horizon and in time slice to interpret the environments of the earliest Quaternary prior to the onset of glaciation. Combined with analysis of aligned elongate furrows over 10 km long, 100 m wide and 100 m deep suggest a deep marine environment in an almost enclosed basin with persistent strong NW-SE bottom currents in the deepest parts. Pockmarks were formed by the escape of shallow gas on the sides of a small delta in the eastern part of the basin. The progradation of large deltas from both the north and south into the basin make up the majority of the deposition of sediment into the basin. Key Words: base-Quaternary; seismic interpretation; paleoenvironments References: Gatliff, R.W, Richards, P.C, Smith, K, Graham, C.C, McCormac, M, Smith, N.J.P, Long, D, Cameron, T.D.J, Evans, D, Stevenson, A.G, Bulat, J, Ritchie, J.D, (1994) 'United Kingdom offshore regional

Persistent and non-persistent strains of Listeria monocytogenes: A focus on growth kinetics under different temperature, salt, and pH conditions and their sensitivity to sanitizers.

PubMed

Magalhães, R; Ferreira, V; Brandão, T R S; Palencia, R Casquete; Almeida, G; Teixeira, P

2016-08-01

This study aimed to investigate the effect of different conditions, including temperature (37 °C, 22 °C, and 4 °C), NaCl concentrations (2.5%, 4%, and 8%), and acidity (pH = 5), on the growth response of persistent and non-persistent isolates of Listeria monocytogenes. The resistance to two common sanitizers (benzalkonium chloride and hydrogen peroxide) was also investigated. A selected group of 41 persistent and non-persistent L. monocytogenes isolates recovered from three cheese processing plants during a previous longitudinal study was assembled. Average lag time was similar for persistent and non-persistent isolates grown at 37 °C, 22 °C and 4 °C but significantly shorter (p < 0.05) for persistent isolates grown at 2.5%, 4% and 8% NaCl, and at pH 5. Average growth rates were significantly higher (p < 0.05) for persistent than for non-persistent isolates when grown at 22 °C, 2.5%, 4% and 8% NaCl, and at pH 5. These results suggest that persistent strains may be better adapted to grow under stressful conditions frequently encountered in food processing environments than non-persistent strains. No relation between persistence and resistance to the tested sanitizers was found. Copyright © 2016 Elsevier Ltd. All rights reserved.

Persistent and susceptible bacteria with individual deaths.

PubMed

Zucca, Fabio

2014-02-21

The aim of this paper is to study two models for a bacterial population subject to antibiotic treatments. It is known that some bacteria are not sensitive to antibiotics. These bacteria, called persisters, are in a state called persistence and each bacterium can switch from this state to a non-persistent (or susceptible) state and back (with rates b and a respectively). Our models extend those introduced in Garet et al. (2012) by adding a random natural life cycle for each bacterium and by allowing bacteria in the susceptible state to escape the action of the antibiotic with a fixed probability 1-p (while every bacterium in a persistent state survives with probability 1). This last mechanism of survival to the antibiotics differs from the persistent state one (where reproduction is forbidden) since in this case the bacterium can replicate. We study two different models. In the first model we "inject" the antibiotics in the system at fixed, deterministic times while in the second one the time intervals are random. We show that, in order to kill eventually the whole bacterial population, these time intervals cannot be "too large". The maximum admissible length is increasing with respect to p; we see that even when p is close to 1, this interval length can be significantly smaller than in the case p=1. While in the case p=1 switching back and forth to the persistent state is the only chance of surviving for bacteria, when p<1 and the death rate in the persistent state, say dr, is positive then the situation is more complex. In this case our model suggests that if dr and b are positive (and fixed) then for higher values of p there is an interval for the rate a, say (0,ap) where switching to the persistent state is a good strategy while for a>ap the situation is less favorable than a=0. On the other hand, for smaller values of p the best strategy is a=0, that is, not switching. Finally, when dr=0, switching to the susceptible state is always a better strategy, from the

Antiphospholipid Antibodies and Recurrent Thrombotic Events: Persistence and Portfolio.

PubMed

Amory, Colum F; Levine, Steven R; Brey, Robin L; Gebregziabher, Mulugeta; Tuhrim, Stanley; Tilley, Barbara C; Simpson, Ann-Catherin C; Sacco, Ralph L; Mohr, Jay P

2015-01-01

There are very limited prospective data on the significance of persistent antiphospholipid antibodies (aPL) and recurrent thrombo-occlusive events (TOEs). We investigated the prognostic value of (1) 2 newer aPL assays, (2) an aPL portfolio and (3) persistent aPL positivity following stroke. A total of 1,770 subjects from the APASS-WARSS study underwent further aPL testing for antibodies to phosphatidylserine (aPS) and anti-β2-glycoprotein-I (anti-β2GPI) from stored sera. Follow-up aPL status was also tested in a subset of subjects. Primary analysis was based on time to any TOE (ischemic stroke, myocardial infarction, transient ischemic attack, deep vein thrombosis, pulmonary embolism or systemic arterial occlusion)/death at 2 years. Cox proportional hazard analyses assessed whether aPL independently related to outcome. Persistent anti-β2GPI decreased the time to TOE/death after adjustment for potential confounders (hazards ratio (HR) 2.86, 95% CI 1.21-6.76, p = 0.017). When persistent anti-β2GPI was combined with another persistently positive aPL, time to TOE/death was also reduced (HR 3.79, 95% CI 1.18-12.14, p = 0.025). Neither persistent anticardiolipin antibodies nor persistent aPS alone nor a single positive anti-β2GPI nor aPS was associated with decreased time to TOE/death. No single positive aPL, portfolio of baseline aPL or any persistent aPL increased the rate of TOE/death. Rates of TOE/death were not influenced by aPL results at baseline or follow-up. Persistent anti-β2GPI alone, and with persistent second aPL, was independently associated with decreased time to TOE/death. Persistent aPL, an aPL portfolio and newer aPL in ischemic stroke patients are not helpful in predicting an increased rate of recurrent TOEs. © 2015 S. Karger AG, Basel.

Measles virus induces persistent infection by autoregulation of viral replication.

PubMed

Doi, Tomomitsu; Kwon, Hyun-Jeong; Honda, Tomoyuki; Sato, Hiroki; Yoneda, Misako; Kai, Chieko

2016-11-24

Natural infection with measles virus (MV) establishes lifelong immunity. Persistent infection with MV is likely involved in this phenomenon, as non-replicating protein antigens never induce such long-term immunity. Although MV establishes stable persistent infection in vitro and possibly in vivo, the mechanism by which this occurs is largely unknown. Here, we demonstrate that MV changes the infection mode from lytic to non-lytic and evades the innate immune response to establish persistent infection without viral genome mutation. We found that, in the persistent phase, the viral RNA level declined with the termination of interferon production and cell death. Our analysis of viral protein dynamics shows that during the establishment of persistent infection, the nucleoprotein level was sustained while the phosphoprotein and large protein levels declined. The ectopic expression of nucleoprotein suppressed viral replication, indicating that viral replication is self-regulated by nucleoprotein accumulation during persistent infection. The persistently infected cells were able to produce interferon in response to poly I:C stimulation, suggesting that MV does not interfere with host interferon responses in persistent infection. Our results may provide mechanistic insight into the persistent infection of this cytopathic RNA virus that induces lifelong immunity.

Persistent challenging behaviour in people with an intellectual disability.

PubMed

Totsika, Vasiliki; Hastings, Richard P

2009-09-01

The aim of the present review is to summarize recent research findings on the persistence of challenging behaviours in adults and children with an intellectual disability. Studies varied in their definition and measurement of persistence or change in challenging behaviours. Persistence levels tended to be high in adults and challenging behaviours were stable over time, especially in individuals with autism. Moderate to high stability levels were evident in children, although there was a tendency for decreases in mean scores for behaviour problems over time. A substantial proportion of people with an intellectual disability experience persistent and stable challenging behaviours across their lives. Our knowledge of the factors that drive these high levels of persistence remains limited.

Scaldiporia vandokkumi, a new pontoporiid (Mammalia, Cetacea, Odontoceti) from the Late Miocene to earliest Pliocene of the Westerschelde estuary (The Netherlands)

PubMed Central

Louwye, Stephen; Lambert, Olivier

2017-01-01

Background The family Pontoporiidae (Cetacea, Odontoceti, Inioidea) is currently represented in our oceans by just one species of diminutive dolphin (Pontoporia blainvillei, franciscana). Although P. blainvillei is limited to coastal waters of the South Atlantic along Brazil, Uruguay and Argentina, multiple Miocene and Pliocene fossils indicate the past presence of members of the family in the South Atlantic, South Paciifc and North Atlantic oceans. Our comprehension of the origin and diversity of this clade and of the relationships of its members with other inioids is hampered by the fact that part of the described fossil specimens, especially from the North Atlantic realm, are cranial fragments often associated to limited stratigraphic information. Methods Based on an almost complete fossil cranium of pontoporiid from the Westerschelde estuary, The Netherlands, whose preservation allows for detailed morphological observations, we describe a new genus and species. The latter is compared to other pontoporiids, as well as a few non-pontoporiid inioids. A phylogenetic analysis is performed to investigate the relationship of S. vandokkumi with the best-known extinct and extant inioids. Palynological analysis of the sediment associated to the holotype is used to assess its geological age. Results and discussion The new genus and species Scaldiporia vandokkumi is characterized among others by greatly thickened premaxillary eminences reaching the level of the antorbital notch. Palynologically dated from the late Tortonian—earliest Zanclean (7.6–5 Ma, Late Miocene—earliest Pliocene), this new pontoporiid confirms the surprising past diversity of marine inioids in the North Atlantic area. Finally the content of the pontoporiid subfamily Brachydelphininae is briefly discussed. PMID:29109917

Risk factors for persistent gestational trophoblastic neoplasia.

PubMed

Kuyumcuoglu, Umur; Guzel, Ali Irfan; Erdemoglu, Mahmut; Celik, Yusuf

2011-01-01

This retrospective study evaluated the risk factors for persistent gestational trophoblastic disease (GTN) and determined their odds ratios. This study included 100 cases with GTN admitted to our clinic. Possible risk factors recorded were age, gravidity, parity, size of the neoplasia, and beta-human chorionic gonadotropin levels (beta-hCG) before and after the procedure. Statistical analyses consisted of the independent sample t-test and logistic regression using the statistical package SPSS ver. 15.0 for Windows (SPSS, Chicago, IL, USA). Twenty of the cases had persistent GTN, and the differences between these and the others cases were evaluated. The size of the neoplasia and histopathological type of GTN had no statistical relationship with persistence, whereas age, gravidity, and beta-hCG levels were significant risk factors for persistent GTN (p < 0.05). The odds ratios (95% confidence interval (CI)) for age, gravidity, and pre- and post-evacuation beta-hCG levels determined using logistic regression were 4.678 (0.97-22.44), 7.315 (1.16-46.16), 2.637 (1.41-4.94), and 2.339 (1.52-3.60), respectively. Patient age, gravidity, and beta-hCG levels were risk factors for persistent GTN, whereas the size of the neoplasia and histopathological type of GTN were not significant risk factors.

Emergence of Persistent Infection due to Heterogeneity

NASA Astrophysics Data System (ADS)

Agrawal, Vidit; Moitra, Promit; Sinha, Sudeshna

2017-02-01

We explore the emergence of persistent infection in a closed region where the disease progression of the individuals is given by the SIRS model, with an individual becoming infected on contact with another infected individual. We investigate the persistence of contagion qualitatively and quantitatively, under increasing heterogeneity in the partitioning of the population into different disease compartments, as well as increasing heterogeneity in the phases of the disease among individuals within a compartment. We observe that when the initial population is uniform, consisting of individuals at the same stage of disease progression, infection arising from a contagious seed does not persist. However when the initial population consists of randomly distributed refractory and susceptible individuals, a single source of infection can lead to sustained infection in the population, as heterogeneity facilitates the de-synchronization of the phases in the disease cycle of the individuals. We also show how the average size of the window of persistence of infection depends on the degree of heterogeneity in the initial composition of the population. In particular, we show that the infection eventually dies out when the entire initial population is susceptible, while even a few susceptibles among an heterogeneous refractory population gives rise to a large persistent infected set.

STUDY DESIGN FOR A PILOT STUDY OF CHILDREN'S TOTAL EXPOSURE TO PERSISTENT PESTICIDES AND OTHER PERSISTENT ORGANIC PESTICIDES "CTEPP"

EPA Science Inventory

The Children's Total Exposure to Persistent Pesticides and Other Persistent Pollutant (CTEPP) study is one of the largest aggregate exposure studies of young children in the United States. The CTEPP study examines the exposures of about 260 preschool children and their primary ad...

Persistent Structural Priming from Language Comprehension to Language Production

ERIC Educational Resources Information Center

Bock, Kathryn; Dell, Gary S.; Chang, Franklin; Onishi, Kristine H.

2007-01-01

To examine the relationship between syntactic processes in language comprehension and language production, we compared structural persistence from sentence primes that speakers heard to persistence from primes that speakers produced. [Bock, J. K., & Griffin, Z. M. (2000). The persistence of structural priming: transient activation or implicit…

Evaluating Chemical Persistence in a Multimedia Environment: ACART Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, D.H.; McKone, T.E.; Kastenberg, W.E.

1999-02-01

For the thousands of chemicals continuously released into the environment, it is desirable to make prospective assessments of those likely to be persistent. Persistent chemicals are difficult to remove if adverse health or ecological effects are later discovered. A tiered approach using a classification scheme and a multimedia model for determining persistence is presented. Using specific criteria for persistence, a classification tree is developed to classify a chemical as ''persistent'' or ''non-persistent'' based on the chemical properties. In this approach, the classification is derived from the results of a standardized unit world multimedia model. Thus, the classifications are more robustmore » for multimedia pollutants than classifications using a single medium half-life. The method can be readily implemented and provides insight without requiring extensive and often unavailable data. This method can be used to classify chemicals when only a few properties are known and be used to direct further data collection. Case studies are presented to demonstrate the advantages of the approach.« less

Indigenous Arabs are descendants of the earliest split from ancient Eurasian populations

PubMed Central

Rodriguez-Flores, Juan L.; Fakhro, Khalid; Agosto-Perez, Francisco; Ramstetter, Monica D.; Arbiza, Leonardo; Vincent, Thomas L.; Robay, Amal; Malek, Joel A.; Suhre, Karsten; Chouchane, Lotfi; Badii, Ramin; Al-Nabet Al-Marri, Ajayeb; Abi Khalil, Charbel; Zirie, Mahmoud; Jayyousi, Amin; Salit, Jacqueline; Keinan, Alon; Clark, Andrew G.; Crystal, Ronald G.; Mezey, Jason G.

2016-01-01

An open question in the history of human migration is the identity of the earliest Eurasian populations that have left contemporary descendants. The Arabian Peninsula was the initial site of the out-of-Africa migrations that occurred between 125,000 and 60,000 yr ago, leading to the hypothesis that the first Eurasian populations were established on the Peninsula and that contemporary indigenous Arabs are direct descendants of these ancient peoples. To assess this hypothesis, we sequenced the entire genomes of 104 unrelated natives of the Arabian Peninsula at high coverage, including 56 of indigenous Arab ancestry. The indigenous Arab genomes defined a cluster distinct from other ancestral groups, and these genomes showed clear hallmarks of an ancient out-of-Africa bottleneck. Similar to other Middle Eastern populations, the indigenous Arabs had higher levels of Neanderthal admixture compared to Africans but had lower levels than Europeans and Asians. These levels of Neanderthal admixture are consistent with an early divergence of Arab ancestors after the out-of-Africa bottleneck but before the major Neanderthal admixture events in Europe and other regions of Eurasia. When compared to worldwide populations sampled in the 1000 Genomes Project, although the indigenous Arabs had a signal of admixture with Europeans, they clustered in a basal, outgroup position to all 1000 Genomes non-Africans when considering pairwise similarity across the entire genome. These results place indigenous Arabs as the most distant relatives of all other contemporary non-Africans and identify these people as direct descendants of the first Eurasian populations established by the out-of-Africa migrations. PMID:26728717

Persistence of Undergraduate Women in STEM Fields

ERIC Educational Resources Information Center

Pedone, Maggie Helene

2016-01-01

The underrepresentation of women in science, technology, engineering, and mathematics (STEM) is a complex problem that continues to persist at the postsecondary level, particularly in computer science and engineering fields. This dissertation explored the pre-college and college level factors that influenced undergraduate women's persistence in…

Characterization of multi-drug tolerant persister cells in Streptococcus suis

PubMed Central

2014-01-01

Background Persister cells constitute a subpopulation of dormant cells within a microbial population which are genetically identical but phenotypically different to regular cells. Notably, persister cells show an elevated tolerance to antimicrobial agents. Thus, they are considered to represent a microbial ‘bet-hedging’ strategy and are of particular importance in pathogenic bacteria. Results We studied the ability of the zoonotic pathogen Streptococcus (S.) suis to form multi-drug tolerant variants and identified persister cells dependent on the initial bacterial growth phase. We observed lower numbers of persisters in exponential phase cultures than in stationary growth phase populations. S. suis persister cells showed a high tolerance to a variety of antibiotics, and the phenotype was not inherited as tested with four passages of S. suis populations. Furthermore, we provide evidence that the persister phenotype is related to expression of genes involved in general metabolic pathways since we found higher numbers of persister cells in a mutant strain defective in the catabolic arginine deiminase system as compared to its parental wild type strain. Finally, we observed persister cell formation also in other S. suis strains and pathogenic streptococcal species. Conclusions Taken together, this is the first study that reports multi-drug tolerant persister cells in the zoonotic pathogen S. suis. PMID:24885389

Characterization of multi-drug tolerant persister cells in Streptococcus suis.

PubMed

Willenborg, Jörg; Willms, Daniela; Bertram, Ralph; Goethe, Ralph; Valentin-Weigand, Peter

2014-05-12

Persister cells constitute a subpopulation of dormant cells within a microbial population which are genetically identical but phenotypically different to regular cells. Notably, persister cells show an elevated tolerance to antimicrobial agents. Thus, they are considered to represent a microbial 'bet-hedging' strategy and are of particular importance in pathogenic bacteria. We studied the ability of the zoonotic pathogen Streptococcus (S.) suis to form multi-drug tolerant variants and identified persister cells dependent on the initial bacterial growth phase. We observed lower numbers of persisters in exponential phase cultures than in stationary growth phase populations. S. suis persister cells showed a high tolerance to a variety of antibiotics, and the phenotype was not inherited as tested with four passages of S. suis populations. Furthermore, we provide evidence that the persister phenotype is related to expression of genes involved in general metabolic pathways since we found higher numbers of persister cells in a mutant strain defective in the catabolic arginine deiminase system as compared to its parental wild type strain. Finally, we observed persister cell formation also in other S. suis strains and pathogenic streptococcal species. Taken together, this is the first study that reports multi-drug tolerant persister cells in the zoonotic pathogen S. suis.

Persistence among Minority STEM Majors: A Phenomenological Study

NASA Astrophysics Data System (ADS)

Williams-Watson, Stacey

The United States needs to increase the number of science, technology, engineering, and math (STEM) graduates to remain competitive in the global market and maintain national security. Minority students, specifically African-American and Hispanic, are underrepresented in STEM fields. As the minority population continues to grow it is essential that higher education institutions improve minority students' persistence in STEM education. This study examined the problem of minority students' lack of persistence in STEM programs. The purpose of this qualitative transcendental phenomenological study was to describe the lived experiences that minority students perceived as contributing to their persistence in STEM. The central research question was: What are the lived experiences of minority STEM students that have contributed to their persistence in a STEM program? The sub-questions were: a) What led participants to majors in STEM?; b) What contributed to students' success and persistence in STEM?; and c) What advice do students have to offer? The researcher interviewed 12 minority STEM students and uncovered 10 themes that described the lived experiences of minority students' persistence in STEM programs. The themes were 1) Childhood experiences and interests; 2) Positive educational experiences in secondary school; 3) Self- motivation; 4) Positive experiences with professors; 5) Family encouragement and values; 6) Lack of minorities; 7) Lack of educational preparation; 8) The need for financial assistance; 9) Clubs and organizations; and 10) Friends within the major. The significance of these findings is the potential to produce changes in curricula, programs, and retention methods that may improve the persistence of minority students in STEM programs.

Persistence of undergraduate women in STEM fields

NASA Astrophysics Data System (ADS)

Pedone, Maggie Helene

The underrepresentation of women in science, technology, engineering, and mathematics (STEM) is a complex problem that continues to persist at the postsecondary level, particularly in computer science and engineering fields. This dissertation explored the pre-college and college level factors that influenced undergraduate women's persistence in STEM. This study also examined and compared the characteristics of undergraduate women who entered STEM fields and non-STEM fields in 2003-2004. The nationally representative Beginning Postsecondary Students Longitudinal Study (BPS:04/09) data set was used for analysis. BPS:04/09 study respondents were surveyed three times (NPSAS:04, BPS:04/06, BPS:04/09) over a six-year period, which enabled me to explore factors related to long-term persistence. Astin's Input-Environment-Output (I-E-O) model was used as the framework to examine student inputs and college environmental factors that predict female student persistence (output) in STEM. Chi-square tests revealed significant differences between undergraduate women who entered STEM and non-STEM fields in 2003-2004. Differences in student demographics, prior academic achievement, high school course-taking patterns, and student involvement in college such as participation in study groups and school clubs were found. Notably, inferential statistics showed that a significantly higher proportion of female minority students entered STEM fields than non-STEM fields. These findings challenge the myth that underrepresented female minorities are less inclined to enter STEM fields. Logistic regression analyses revealed thirteen significant predictors of persistence for undergraduate women in STEM. Findings showed that undergraduate women who were younger, more academically prepared, and academically and socially involved in college (e.g., lived on campus, interacted with faculty, participated in study groups, fine arts activities, and school sports) were more likely to persist in STEM

The origins of lactase persistence in Europe.

PubMed

Itan, Yuval; Powell, Adam; Beaumont, Mark A; Burger, Joachim; Thomas, Mark G

2009-08-01

Lactase persistence (LP) is common among people of European ancestry, but with the exception of some African, Middle Eastern and southern Asian groups, is rare or absent elsewhere in the world. Lactase gene haplotype conservation around a polymorphism strongly associated with LP in Europeans (-13,910 C/T) indicates that the derived allele is recent in origin and has been subject to strong positive selection. Furthermore, ancient DNA work has shown that the--13,910*T (derived) allele was very rare or absent in early Neolithic central Europeans. It is unlikely that LP would provide a selective advantage without a supply of fresh milk, and this has lead to a gene-culture coevolutionary model where lactase persistence is only favoured in cultures practicing dairying, and dairying is more favoured in lactase persistent populations. We have developed a flexible demic computer simulation model to explore the spread of lactase persistence, dairying, other subsistence practices and unlinked genetic markers in Europe and western Asia's geographic space. Using data on--13,910*T allele frequency and farming arrival dates across Europe, and approximate Bayesian computation to estimate parameters of interest, we infer that the--13,910*T allele first underwent selection among dairying farmers around 7,500 years ago in a region between the central Balkans and central Europe, possibly in association with the dissemination of the Neolithic Linearbandkeramik culture over Central Europe. Furthermore, our results suggest that natural selection favouring a lactase persistence allele was not higher in northern latitudes through an increased requirement for dietary vitamin D. Our results provide a coherent and spatially explicit picture of the coevolution of lactase persistence and dairying in Europe.

Rotenone persistence model for montane streams

USGS Publications Warehouse

Brown, Peter J.; Zale, Alexander V.

2012-01-01

The efficient and effective use of rotenone is hindered by its unknown persistence in streams. Environmental conditions degrade rotenone, but current label instructions suggest fortifying the chemical along a stream based on linear distance or travel time rather than environmental conditions. Our objective was to develop models that use measurements of environmental conditions to predict rotenone persistence in streams. Detailed measurements of ultraviolet radiation, water temperature, dissolved oxygen, total dissolved solids (TDS), conductivity, pH, oxidation–reduction potential (ORP), substrate composition, amount of organic matter, channel slope, and travel time were made along stream segments located between rotenone treatment stations and cages containing bioassay fish in six streams. The amount of fine organic matter, biofilm, sand, gravel, cobble, rubble, small boulders, slope, pH, TDS, ORP, light reaching the stream, energy dissipated, discharge, and cumulative travel time were each significantly correlated with fish death. By using logistic regression, measurements of environmental conditions were paired with the responses of bioassay fish to develop a model that predicted the persistence of rotenone toxicity in streams. This model was validated with data from two additional stream treatment reaches. Rotenone persistence was predicted by a model that used travel time, rubble, and ORP. When this model predicts a probability of less than 0.95, those who apply rotenone can expect incomplete eradication and should plan on fortifying rotenone concentrations. The significance of travel time has been previously identified and is currently used to predict rotenone persistence. However, rubble substrate, which may be associated with the degradation of rotenone by adsorption and volatilization in turbulent environments, was not previously considered.

Measles virus, immune control and persistence

PubMed Central

Griffin, Diane E.; Lin, Wen-Hsuan; Pan, Chien-Hsiung

2012-01-01

Measles remains one of the most important causes of child morbidity and mortality worldwide with the greatest burden in the youngest children. Most acute measles deaths are due to secondary infections that result from a poorly understood measles-induced suppression of immune responses. Young children are also vulnerable to late development of subacute sclerosing panencephalitis, a progressive, uniformly fatal neurologic disease caused by persistent measles virus (MeV) infection. During acute infection, the rash marks the appearance of the adaptive immune response and CD8+ T cell-mediated clearance of infectious virus. However, after clearance of infectious virus, MeV RNA persists and can be detected in blood, respiratory secretions, urine and lymphoid tissue for many weeks to months. This prolonged period of virus clearance may help to explain measles immunosuppression and the development of lifelong immunity to re-infection, as well as occasional infection of the nervous system. Once MeV infects neurons, the virus can spread transynaptically and the envelope proteins needed to form infectious virus are unnecessary, accumulate mutations and can establish persistent infection. Identification of the immune mechanisms required for clearance of MeV RNA from multiple sites will enlighten our understanding of the development of disease due to persistent infection. PMID:22316382

Revisiting the concept of recalcitrance and organic matter persistence in soils and aquatic systems: Does environment trump chemistry?

NASA Astrophysics Data System (ADS)

Marin-Spiotta, E.

2014-12-01

Most ecological models of decomposition rely on plant litter chemistry. However, growing evidence suggests that the chemical composition of organic matter (OM) is not a good predictor of its eventual fate in terrestrial or aquatic environments. New data on variable decomposition rates of select organic compounds challenge concepts of chemical recalcitrance, i.e. the inherent ability of certain molecular structures to resist biodegradation. The role of environmental or "ecosystem" properties on influencing decomposition dates back to some of the earliest research on soil OM. Despite early recognition that the physical and aqueous matrices are critical in determining the fate of organic compounds, the prevailing paradigm hinges on intrinsic chemical properties as principal predictors of decay rate. Here I build upon recent reviews and discuss new findings that contribute to three major transformations in our understanding of OM persistence: (1) a shift away from an emphasis on chemical recalcitrance as a primary predictor of turnover, (2) new interpretations of radiocarbon ages which challenge predictions of reactivity, and (3) the recognition that most detrital OM accumulating in soils and in water has been microbially processed. Predictions of OM persistence due to aromaticity are challenged by high variability in lignin and black C turnover observed in terrestrial and aquatic environments. Contradictions in the behavior of lignin are, in part, influenced by inconsistent methodologies among research communities. Even black C, long considered to be one of the most recalcitrant components of OM, is susceptible to biodegradation, challenging predictions of the stability of aromatic structures. At the same time, revised interpretations of radiocarbon data suggest that organic compounds can acquire long mean residence times by various mechanisms independent of their molecular structure. Understanding interactions between environmental conditions and biological

Starless Clumps and the Earliest Phases of High-mass Star Formation in the Milky Way

NASA Astrophysics Data System (ADS)

Svoboda, Brian

2018-01-01

High-mass stars are key to regulating the interstellar medium, star formation activity, and overall evolution of galaxies, but their formation remains an open problem in astrophysics. In order to understand the physical conditions during the earliest phases of high-mass star formation, I report on observational studies of dense starless clump candidates (SCCs) that show no signatures of star formation activity. I identify 2223 SCCs from the 1.1 mm Bolocam Galactic Plane Survey, systematically analyze their physical properties, and show that the starless phase is not represented by a single timescale, but evolves more rapidly with increasing clump mass. To investigate the sub-structure in SCCs at high spatial resolution, I study the 12 most high-mass SCCs within 5 kpc using ALMA. I report previously undetected low-luminosity protostars in 11 out of 12 SCCs, fragmentation equal to the thermal Jeans length of the clump, and no starless cores exceeding 30 solar masses. While uncertainties remain concerning the star formation effeciency in this sample, these observational facts are consistent with models where high-mass stars form from intially low- to intermediate-mass protostars that accrete most of their mass from the surrounding clump.

Basal tissue structure in the earliest euconodonts: Testing hypotheses of developmental plasticity in euconodont phylogeny

USGS Publications Warehouse

Dong, X.-P.; Donoghue, P.C.J.; Repetski, J.E.

2005-01-01

The hypothesis that conodonts are vertebrates rests solely on evidence of soft tissue anatomy. This has been corroborated by microstructural, topological and developmental evidence of homology between conodont and vertebrate hard tissues. However, these conclusions have been reached on the basis of evidence from highly derived euconodont taxa and the degree to which they are representative of plesiomorphic euconodonts remains an open question. Furthermore, the range of variation in tissue types comprising the euconodont basal body has been used to establish a hypothesis of developmental plasticity early in the phylogeny of the clade, and a model of diminishing potentiality in the evolution of development systems. The microstructural fabrics of the basal tissues of the earliest euconodonts (presumed to be the most plesiomorphic) are examined to test these two hypotheses. It is found that the range of microstructural variation observed hitherto was already apparent among plesiomorphic euconodonts. Thus, established histological data are representative of the most plesiomorphic euconodonts. However, although there is evidence of a range in microstructural fabrics, these are compatible with the dentine tissue system alone, and the degree of variation is compatible with that seen in clades of comparable diversity. ?? The Palaeontological Association.

Student Financial Aid and Persistence in College.

ERIC Educational Resources Information Center

Astin, Helen S.; Cross, Patricia H.

The administration, purpose, and design of student financial aid programs are examined with emphasis on assuring greater access to higher education, student persistence, and providing students with incentives for performing well academically. After a brief history of financial aid and a review of selected studies on persistence, the sampling and…

Persistence in Science: Gender and Program Differences.

ERIC Educational Resources Information Center

Boisset, Annick; And Others

This study was conducted to investigate persistence rates and gender differences among science students at John Abbott College (JAC). Issues addressed in the study included the differences between students persisting in and those transferring out of science programs, female representation in science programs at JAC, and the differences, if any,…

Statistical Inference for Porous Materials using Persistent Homology.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moon, Chul; Heath, Jason E.; Mitchell, Scott A.

2017-12-01

We propose a porous materials analysis pipeline using persistent homology. We rst compute persistent homology of binarized 3D images of sampled material subvolumes. For each image we compute sets of homology intervals, which are represented as summary graphics called persistence diagrams. We convert persistence diagrams into image vectors in order to analyze the similarity of the homology of the material images using the mature tools for image analysis. Each image is treated as a vector and we compute its principal components to extract features. We t a statistical model using the loadings of principal components to estimate material porosity, permeability,more » anisotropy, and tortuosity. We also propose an adaptive version of the structural similarity index (SSIM), a similarity metric for images, as a measure to determine the statistical representative elementary volumes (sREV) for persistence homology. Thus we provide a capability for making a statistical inference of the uid ow and transport properties of porous materials based on their geometry and connectivity.« less

Presynaptic learning and memory with a persistent firing neuron and a habituating synapse: a model of short term persistent habituation.

PubMed

Ramanathan, Kiruthika; Ning, Ning; Dhanasekar, Dhiviya; Li, Guoqi; Shi, Luping; Vadakkepat, Prahlad

2012-08-01

Our paper explores the interaction of persistent firing axonal and presynaptic processes in the generation of short term memory for habituation. We first propose a model of a sensory neuron whose axon is able to switch between passive conduction and persistent firing states, thereby triggering short term retention to the stimulus. Then we propose a model of a habituating synapse and explore all nine of the behavioral characteristics of short term habituation in a two neuron circuit. We couple the persistent firing neuron to the habituation synapse and investigate the behavior of short term retention of habituating response. Simulations show that, depending on the amount of synaptic resources, persistent firing either results in continued habituation or maintains the response, both leading to longer recovery times. The effectiveness of the model as an element in a bio-inspired memory system is discussed.

Persistence of atopic dermatitis (AD): A systematic review and meta-analysis

PubMed Central

Kim, Jooho P.; Chao, Lucy X.; Simpson, Eric L.; Silverberg, Jonathan I.

2016-01-01

Background Previous studies found conflicting results about whether childhood atopic dermatitis (AD) persists into adulthood. Objective We sought to determine persistence rates and clinical factors associated with prolonged AD. Methods A systematic review was performed in MEDLINE, EMBASE, Scopus, GREAT, LILACS, Web of Science, Academic Search Complete, and Cochrane Library. Meta-analysis was performed using Kaplan-Meier plots and random-effects proportional hazards regression. Results In total, 45 studies including 110,651 subjects spanning 434,992 patient-years from 15 countries were included. In pooled analysis, 80% of childhood AD did not persist by 8 years and less than 5% persisted by 20 years after diagnosis (mean ± SE: 6.1 ± 0.02 years). Children with AD that persisted already for more than 10 years (8.3 ± 0.08 years) had longer persistence than those with 3 (3.2 ± 0.02 years) or 5 (6.8 ± 0.06 years) years of persistence. Children who developed AD by age 2 years had less persistent disease (P < .0001). Persistence was greater in studies using patient-/caregiver-assessed versus physician-assessed outcomes, female versus male patients (P ≤ .0006), but not in those with sensitivity to allergens (P = .90). Three studies found prolonged persistence with more severe AD. Limitations Some studies did not capture recurrences later in life. Conclusions Most childhood AD remitted by adulthood. However, children with already persistent disease, later onset, and/or more severe disease have increased persistence. PMID:27544489

Clinical characteristics and airway inflammation profile of COPD persistent sputum producers.

PubMed

Khurana, S; Ravi, A; Sutula, J; Milone, R; Williamson, R; Plumb, J; Vestbo, J; Singh, D

2014-12-01

COPD patients with chronic bronchitis include a subgroup with persistent sputum production on most or every day. We hypothesized that COPD patients with persistent sputum production have a different profile of airway inflammation, and more severe clinical characteristics. To compare the airway inflammation profile and clinical characteristics of COPD persistent and non-persistent sputum producers. COPD persistent sputum producers (n = 26) and non-persistent sputum producers (n = 26) underwent sputum induction and pulmonary function tests. Exacerbation history was recorded; the St. George's Respiratory Questionnaire, Modified Medical Research Council Dyspnoea scale and COPD Assessment Tool were completed. 33 COPD patients provided sputum for bacteriology. Persistent sputum producers had lower post-bronchodilator FEV1% predicted (p = 0.01), diffusion capacity (p = 0.04), 6 min walk test distance (p = 0.05), and higher closing volume (p = 0.01), BODE index (p = 0.01), rate of bacterial colonization (p = 0.004) and exacerbations (p = 0.03) compared to non-persistent sputum producers. The mean SGRQ and CAT scores were higher in persistent sputum producers (p = 0.01 and 0.03 respectively). Sputum neutrophil and eosinophil total cell counts were higher in persistent sputum producers (p = 0.02 and 0.05 respectively). Sputum levels of eotaxin (p = 0.02), MCP-1 (p = 0.02), TNF-α (p = 0.03) and IL-6 (p = 0.05) were higher in persistent sputum producers. COPD persistent sputum producers have more severe clinical characteristics and increased concentrations of some inflammatory mediators in the airways.

Generating Dynamic Persistence in the Time Domain

NASA Astrophysics Data System (ADS)

Guerrero, A.; Smith, L. A.; Smith, L. A.; Kaplan, D. T.

2001-12-01

Many dynamical systems present long-range correlations. Physically, these systems vary from biological to economical, including geological or urban systems. Important geophysical candidates for this type of behaviour include weather (or climate) and earthquake sequences. Persistence is characterised by slowly decaying correlation function; that, in theory, never dies out. The Persistence exponent reflects the degree of memory in the system and much effort has been expended creating and analysing methods that successfully estimate this parameter and model data that exhibits persistence. The most widely used methods for generating long correlated time series are not dynamical systems in the time domain, but instead are derived from a given spectral density. Little attention has been drawn to modelling persistence in the time domain. The time domain approach has the advantage that an observation at certain time can be calculated using previous observations which is particularly suitable when investigating the predictability of a long memory process. We will describe two of these methods in the time domain. One is a traditional approach using fractional ARIMA (autoregressive and moving average) models; the second uses a novel approach to extending a given series using random Fourier basis functions. The statistical quality of the two methods is compared, and they are contrasted with weather data which shows, reportedly, persistence. The suitability of this approach both for estimating predictability and for making predictions is discussed.

A Swift Look at SN 2011fe: The Earliest Ultraviolet Observations of a Type Ia Supernova

NASA Technical Reports Server (NTRS)

Oates, Samantha; Holland, Stephen; Immler, Stefan; Brown, Peter J.; Dawson, Kyle S.; DePasquale, Massimiliano; Gronwall, Caryl; Kuin, Paul; Mazzali, Paolo; Miline, Peter;

A new genus and species of micro bee fly from the Earliest Eocene French amber (Diptera: Mythicomyiidae: Psiloderoidinae).

PubMed

Myskowiak, Justine; Garrouste, Romain; Nel, Andre

2016-05-26

Mythicomyiidae, or micro bee flies, are tiny flies (0.5-5.0 mm) that are found throughout most parts of the world except the highest altitudes and latitudes (Greathead & Evenhuis 2001). Including all extinct and extant taxa, the Mythicomyiidae currently comprise more than 380 valid taxonomic species distributed among 30 genera. The subfamily Psiloderoidinae is especially well represented among the fossil Mythicomyiidae by seven Cretaceous or Cenozoic genera. We here describe a new genus and a new species of this subfamily based on fossils from the Earliest Eocene of Oise (France). A Psiloderoidinae, Proplatypygus matilei Nel & DePloëg, 2004, is already described in this amber. Another mythicomyiid, Eurodoliopteryx inexpectatus Nel, 2006, is the most frequent bombylioid in this amber (Nel & DePloëg, 2004; Nel, 2006).

Using Latent Selection Difference to Model Persistence in a Declining Population

PubMed Central

Erickson, Mara E.; Found-Jackson, Christine; Boyce, Mark S.

2014-01-01

Population persistence is a direct measure of the viability of a population. Monitoring the distribution of declining populations or subpopulations over time can yield estimates of persistence, which we show can be modeled as a latent selection difference (LSD) contrasting attributes of sites where populations have persisted versus those that have not. Predicted persistence can be modeled with predictor covariates to identify factors correlated with species persistence. We demonstrate how to model persistence based on changes in occupancy that can include adjustments for detection probability. Using a known historical distribution of the western grebe (Aechmophorus occidentalis), we adapted methods originally developed for occupancy modeling to evaluate how environmental covariates including emergent vegetation and human developments have affected western grebe persistence in Alberta. The relative probability of persistence was correlated with the extent of shoreline bulrush (Scirpus lacustris), which is important vegetation for nesting cover. We also documented that western grebe populations were less likely to persist on lakes in the boreal forest, primarily located on the northern boundary of the species' range. Factors influencing occupancy were different than those determining persistence by western grebes; persistence and occupancy were not correlated. Persistence was more likely on lakes with recreational development, reflecting reliance by grebes on the larger, fish-bearing waterbodies that also are attractive for lakeshore development. Unfortunately, the correlation with recreational development on Alberta's lakes puts grebes at risk for loss of brood-rearing habitats—primary threats to altricial birds—if steps are not taken to prevent disturbance to bulrush stands. Identifying factors related to the persistence of a species—especially one in decline—is a fundamental step in conservation management. PMID:24866172

Persistent RNA virus infections: do PAMPS drive chronic disease?

PubMed Central

McCarthy, Mary K.; Morrison, Thomas E.

2017-01-01

Chronic disease associated with persistent RNA virus infections represents a key public health concern. While human immunodeficiency virus-1 and hepatitis C virus are perhaps the most well-known examples of persistent RNA viruses that cause chronic disease, evidence suggests that many other RNA viruses, including re-emerging viruses such as chikungunya virus, Ebola virus and Zika virus, establish persistent infections. The mechanisms by which RNA viruses drive chronic disease are poorly understood. Here, we discuss how the persistence of viral RNA may drive chronic disease manifestations via the activation of RNA sensing pathways. PMID:28214732

The Origins of Lactase Persistence in Europe

PubMed Central

Itan, Yuval; Powell, Adam; Beaumont, Mark A.; Burger, Joachim; Thomas, Mark G.

2009-01-01

Lactase persistence (LP) is common among people of European ancestry, but with the exception of some African, Middle Eastern and southern Asian groups, is rare or absent elsewhere in the world. Lactase gene haplotype conservation around a polymorphism strongly associated with LP in Europeans (−13,910 C/T) indicates that the derived allele is recent in origin and has been subject to strong positive selection. Furthermore, ancient DNA work has shown that the −13,910*T (derived) allele was very rare or absent in early Neolithic central Europeans. It is unlikely that LP would provide a selective advantage without a supply of fresh milk, and this has lead to a gene-culture coevolutionary model where lactase persistence is only favoured in cultures practicing dairying, and dairying is more favoured in lactase persistent populations. We have developed a flexible demic computer simulation model to explore the spread of lactase persistence, dairying, other subsistence practices and unlinked genetic markers in Europe and western Asia's geographic space. Using data on −13,910*T allele frequency and farming arrival dates across Europe, and approximate Bayesian computation to estimate parameters of interest, we infer that the −13,910*T allele first underwent selection among dairying farmers around 7,500 years ago in a region between the central Balkans and central Europe, possibly in association with the dissemination of the Neolithic Linearbandkeramik culture over Central Europe. Furthermore, our results suggest that natural selection favouring a lactase persistence allele was not higher in northern latitudes through an increased requirement for dietary vitamin D. Our results provide a coherent and spatially explicit picture of the coevolution of lactase persistence and dairying in Europe. PMID:19714206

Strong self-limitation promotes the persistence of rare species.

PubMed

Yenni, Glenda; Adler, Peter B; Ernest, S K Morgan

2012-03-01

Theory has recognized a combination of niche and neutral processes each contributing, with varying importance, to species coexistence. However, long-term persistence of rare species has been difficult to produce in trait-based models of coexistence that incorporate stochastic dynamics, raising questions about how rare species persist despite such variability. Following recent evidence that rare species may experience significantly different population dynamics than dominant species, we use a plant community model to simulate the effect of disproportionately strong negative frequency dependence on the long-term persistence of the rare species in a simulated community. This strong self-limitation produces long persistence times for the rare competitors, which otherwise succumb quickly to stochastic extinction. The results suggest that the mechanism causing species to be rare in this case is the same mechanism allowing those species to persist.

Wolf population persistence in real life

USGS Publications Warehouse

Mech, L.D.; Liberg, O.

2005-01-01

Wolf (Canis lupus) populations tend to be resilient and to persist for long periods, and several characteristics contribute to their resilience and persistence: (1) age of first reproduction (2-3 years), (2) high annual litter size (mean = 6), (3) low dispersal age (1-3 years), and (4) long potential dispersal distance (< 880 km). The only documented factor leading to extinction of well established wolf populations with sufficient food is deliberate poisoning, although conceivably disease could have such an effect.

Bowman's layer encystment in cases of persistent Acanthamoeba keratitis.

PubMed

Yokogawa, Hideaki; Kobayashi, Akira; Yamazaki, Natsuko; Ishibashi, Yasuhisa; Oikawa, Yosaburo; Tokoro, Masaharu; Sugiyama, Kazuhisa

2012-01-01

The purpose of this study was to report Acanthamoeba encystment in Bowman's layer in Japanese cases of persistent Acanthamoeba keratitis (AK). Laser confocal microscopic images of the cornea were obtained in vivo from 18 consecutive eyes from 17 confirmed AK patients. Retrospectively, 14 cases treated over 4 months were categorized as a nonpersistent group and three cases that required prolonged therapy for more than 6 months were categorized as a persistent group. Clinical outcomes based on final best-corrected visual acuity were retrospectively analyzed, and selected confocal images were evaluated qualitatively for abnormal findings. The final best-corrected visual acuity was significantly lower (P < 0.01) for patients in the persistent group compared with that in the nonpersistent group. At the initial visit, in vivo confocal microscopy demonstrated Acanthamoeba cysts exclusively in the epithelial layer in both the nonpersistent group (80%) and the persistent group (100%). At a subsequent follow-up visit, numerous Acanthamoeba cysts were observed in the epithelial cell layer and in Bowman's layer in all patients with persistent AK, but Acanthamoeba cysts were undetectable in all cases with nonpersistent AK tested. Invasion of cysts into Bowman's layer was characteristically observed in patients with persistence of AK. This finding suggests that invasion of Acanthamoeba cysts into Bowman's layer may be a useful predictor for a persistent clinical course.

Earliest isotopic evidence in the Maya region for animal management and long-distance trade at the site of Ceibal, Guatemala

PubMed Central

Emery, Kitty F.; Inomata, Takeshi; Triadan, Daniela; Kamenov, George D.; Krigbaum, John

2018-01-01

This study uses a multiisotope (carbon, nitrogen, oxygen, and strontium) approach to examine early animal management in the Maya region. An analysis of faunal specimens across almost 2,000 years (1000 BC to AD 950) at the site of Ceibal, Guatemala, reveals the earliest evidence for live-traded dogs and possible captive-reared taxa in the Americas. These animals may have been procured for ceremonial functions based on their location in the monumental site core, suggesting that animal management and trade began in the Maya area to promote special events, activities that were critical in the development of state society. Isotopic evidence for animal captivity at Ceibal reveals that animal management played a greater role in Maya communities than previously believed. PMID:29555750

Persistent bacterial infections, antibiotic tolerance, and the oxidative stress response

PubMed Central

Grant, Sarah Schmidt; Hung, Deborah T.

2013-01-01

Certain bacterial pathogens are able to evade the host immune system and persist within the human host. The consequences of persistent bacterial infections potentially include increased morbidity and mortality from the infection itself as well as an increased risk of dissemination of disease. Eradication of persistent infections is difficult, often requiring prolonged or repeated courses of antibiotics. During persistent infections, a population or subpopulation of bacteria exists that is refractory to traditional antibiotics, possibly in a non-replicating or metabolically altered state. This review highlights the clinical significance of persistent infections and discusses different in vitro models used to investigate the altered physiology of bacteria during persistent infections. We specifically focus on recent work establishing increased protection against oxidative stress as a key element of the altered physiologic state across different in vitro models and pathogens. PMID:23563389

Lymphogranuloma venereum causing a persistent genital ulcer.

PubMed

Marcotte, Terrence; Lee, Yer; Pandori, Mark; Jain, Vivek; Cohen, Stephanie Elise

2014-04-01

Lymphogranuloma venereum (LGV) is a sexually transmitted cause of inguinal lymphadenopathy and proctocolitis. We report a patient with a persistent genital ulcer due to LGV (serovar L2b), an unusual presentation among US men who have sex with men. Lymphogranuloma venereum should be considered when evaluating persistent genital ulcers, and LGV-specific testing should be sought.

Survival of bactericidal antibiotic treatment by tolerant persister cells of Klebsiella pneumoniae.

PubMed

Li, Ying; Zhang, Luhua; Zhou, Yingshun; Zhang, Zhikun; Zhang, Xinzhuo

2018-03-01

Persister cells, a subpopulation of tolerant cells within the bacterial culture, are commonly thought to be responsible for antibiotic therapy failure and infection recurrence. Klebsiella pneumoniae is a notorious human pathogen for its increasing resistance to antibiotics and wide involvement in severe infections. In this study, we aimed to investigate the persister subpopulation of K. pneumoniae. The presence of persisters in K. pneumoniae was determined by treatment with high concentrations of antibiotics, used alone or in combination. The effect of low level of antibiotics on persister formation was investigated by pre-exposure of cells to antibiotics with low concentrations followed by higher doses. The dependence of persister levels on growth phase was determined by measuring the survival ability of cells along the growth stages upon exposure to a high concentration of antibiotic. Analysis on persister type was carried out by persister elimination assays.Results/Key findings. We show that K. pneumoniae produces high levels of tolerant persister cells to survive treatment by a variety of high concentrations of bactericidal antibiotics and persister formation is prevalent among K. pneumoniae clinical strains. Besides, we find that persister cells can be induced by low concentrations of antibiotics. Finally, we provide evidence that persister formation is growth phase-dependent and Type II persisters dominate the persister subpopulation during the entire exponential phase of K. pneumoniae. Our study describes the formation of tolerant persister cells that allow survival of treatment by high concentrations of antibiotics in K. pneumoniae.

Persistent ovarian masses and pregnancy outcomes.

PubMed

Goh, William A; Rincon, Monica; Bohrer, Justin; Tolosa, Jorge E; Sohaey, Roya; Riaño, Rene; Davis, James; Zalud, Ivica

2013-07-01

To determine if persistent ovarian masses in pregnancy are associated with increased adverse outcomes. This is a retrospective cohort of 126 pregnant women with a persistent ovarian mass measuring 5 cm or greater who delivered at two university hospitals between 2001 and 2009. Maternal outcomes included gestational age (GA) at diagnosis, delivery and surgery as well as miscarriage, preterm birth (PTB), ovarian torsion and hospital admission for pain. Neonatal outcomes included birth weight, respiratory distress syndrome (RDS), intra-ventricular hemorrhage (IVH), death and sepsis. A total of 1225 ovarian masses were identified (4.9%) in 24,868 patients. A persistent ovarian mass was found in 0.7%. Average GA at diagnosis was 17.8 weeks. Miscarriage rate was 3.3%. Average GA at delivery was 37.9 weeks. Of the patients, 8.5% had ovarian torsion, 10.3% had admission for pain and 9.3% had PTBs. The mean cesarean delivery rate was 46.3%. The average neonatal weight was 3273 g. There was one neonatal death in this cohort. The rate of RDS was 2.8%, IVH 0.9% and neonatal sepsis 1.9%. The most common surgical pathologic diagnosis was dermoids (37.6%). No overt malignancies were seen. A persistent ovarian mass in pregnancy does not confer an increased risk of adverse pregnancy outcomes.

Lesion progression in post-treatment persistent endodontic lesions.

PubMed

Yu, Victoria Soo Hoon; Messer, Harold Henry; Shen, Liang; Yee, Robert; Hsu, Chin-ying Stephen

2012-10-01

Radiographic lesions related to root-filled teeth may persist for long periods after treatment and are considered to indicate failure of initial treatment. Persistent lesions are found in a proportion of cases, but information on lesion progression is lacking. This study examined the incidence of lesion improvement, remaining unchanged, and deterioration among persistent lesions in a group of patients recruited from a university-based clinic and identified potential predictors for lesion progression. Patients of a university clinic with persistent endodontic lesions at least 4 years since treatment and with original treatment radiographs available were recruited with informed consent. Data were obtained by interview and from dental records and clinical and radiographic examinations. Univariate and multivariate statistical analyses were carried out by using SPSS (version 19). One hundred fifty-one persistent lesions were identified in 114 patients. A majority of the lesions (107, 70.9%) received treatment between 4 and 5 years prior. Eighty-six lesions (57.0%) improved, 18 (11.9%) remained unchanged, and 47 (31.1%) deteriorated since treatment. Potential predictors for lesions that did not improve included recall lesion size, pain on biting at recall examination, history of a postobturation flare-up, and a non-ideal root-filling length (P < .05). Lesions that had persisted for a longer period appeared less likely to be improving (relative risk, 1.038; 95% confidence interval, 1.000-1.077). A specific time interval alone should not be used to conclude that a lesion will not resolve without intervention. This study identified several clinical factors that are associated with deteriorating persistent lesions, which should aid in identifying lesions that require further intervention. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Living with persistent rheumatoid arthritis: a BARFOT study.

PubMed

Bala, Sidona-Valentina; Samuelson, Karin; Hagell, Peter; Fridlund, Bengt; Forslind, Kristina; Svensson, Björn; Thomé, Bibbi

2017-09-01

To describe and understand the meaning of living with persistent rheumatoid arthritis. A considerable number of patients with rheumatoid arthritis live with an ongoing active and symptomatic illness despite access to potent antirheumatic treatment. There is, however, a lack of knowledge about the meaning of living with this severe long-term illness, defined as persistent rheumatoid arthritis. A descriptive design based on a hermeneutic phenomenological method was used. Ten adults with persistent rheumatoid arthritis and at least five years disease duration were interviewed. The interviews were analysed according to van Manen's method. Living with persistent rheumatoid arthritis revealed four overall themes: an existence dominated by painful symptoms and treatment, radical changes and limitations in one's life, a continual struggle to cope with one's life and to master the illness, and a dependency on those who are close by and the world around. The lifeworld was affected to a varying extent and in various ways by the illness but also by the dependence on its treatment and care that was not experienced as sufficiently meeting needs in terms of security, access to and coordination of care as well as team and rehabilitation services. Persistent rheumatoid arthritis and its treatment entail a radical effect on the person's life and quality of life. Current ordinary rheumatology care does not seem to meet the individual needs of the person with persistent rheumatoid arthritis in an optimal way. A greater knowledge about and understanding of the person who lives with persistent rheumatoid arthritis is important for facilitating the development of care and the relief of suffering. A holistic alternative to conventional clinical practice, such as person-centred care, could be tested as an innovative model of care. Our findings might serve as material for educational and counselling purposes for healthcare professionals. © 2016 John Wiley & Sons Ltd.

Persistent poliovirus infection of human fetal brain cells.

PubMed

Pavio, N; Buc-Caron, M H; Colbère-Garapin, F

1996-09-01

It has been suggested that poliovirus (PV), the causative agent of poliomyelitis, could persist in surviving patients. We have previously shown that PV can persistently infect some human cell lines in vitro, particularly neuroblastoma cell lines. We report here an ex vivo model in which PV can persistently infect primary cultures of human fetal brain cells. Two mutations involving capsid residues 142 of VP2 and 95 of VP1 were repeatedly selected during the persistent infections. These residues are located in capsid regions known to be involved in interactions between PV and its receptor. During the first week after infection, viral antigens were found in cells of both the neuronal and glial lineages. In contrast, 2 weeks after infection, viral antigens were detected almost exclusively in cells of the neuronal lineage. They were detected predominantly in cells expressing a marker of early commitment to the neuronal lineage, MAP-5, particularly in neuroblasts. Viral antigens were also found in immature progenitors expressing a neuroepithelium marker, nestin, and in cells expressing a marker of postmitotic neurons, MAP-2. The presence of viral antigens in postmitotic neurons suggests that PV can persist in neurons of patients who have survived poliomyelitis.

Some further observations and comments on the earliest role of the father.

PubMed

Abelin, E L

1975-08-01

The longitudinal observation in the family setting of a boy (Michael) during his first two years is used to explore further the earliest role of the father, and to refine my 'early triangulation' model. This model was meant to account for some basic phenomena of Mahler's rapprochement subphase, and was partly based on Piaget's framework. The data are presented along three developmental lines. (1) The specific relationship with father as a different person: the concepts of 'specific refuelling' and of object-specific libido are introduced; and it is suggested that during the subphase of differentiation, all of Michael's specific objects (in particular, the father) shared some 'symbiotic' quality with the mother. (2) On the other hand, qualitative differences of the father relationship were also noted; they confirmed my earlier findings and Mahler's view. (3) Very early, Michael began to acknowledge the relationship with the parents as a couple. After a fleeting indication of rivalry (with mother!), a ritual game of 'getting his parents together' developed at the onset of the rapprochement subphase. This is discussed as one of many possible compromise solutions to avoid the full achievement of the anxiety-provoking 'early triangulation' process. This process, if completed, would involve 'identification with the rival parent', formation of a mental image of the self, and the positive cathexis of neutralized intragroup relationships (which presupposes symbolization). The ubiquitous observation of 'identification with the rival baby' may represent another such compromise solution, and thus a precursor of early triangulation. It might also be a parellel process, leading to 'generational identification' as distinguished from 'gender identification'. The isomorphism of these processes with Piaget's outline of cognitive development is pointed out.

Indigenous Arabs are descendants of the earliest split from ancient Eurasian populations.

PubMed

Rodriguez-Flores, Juan L; Fakhro, Khalid; Agosto-Perez, Francisco; Ramstetter, Monica D; Arbiza, Leonardo; Vincent, Thomas L; Robay, Amal; Malek, Joel A; Suhre, Karsten; Chouchane, Lotfi; Badii, Ramin; Al-Nabet Al-Marri, Ajayeb; Abi Khalil, Charbel; Zirie, Mahmoud; Jayyousi, Amin; Salit, Jacqueline; Keinan, Alon; Clark, Andrew G; Crystal, Ronald G; Mezey, Jason G

2016-02-01

An open question in the history of human migration is the identity of the earliest Eurasian populations that have left contemporary descendants. The Arabian Peninsula was the initial site of the out-of-Africa migrations that occurred between 125,000 and 60,000 yr ago, leading to the hypothesis that the first Eurasian populations were established on the Peninsula and that contemporary indigenous Arabs are direct descendants of these ancient peoples. To assess this hypothesis, we sequenced the entire genomes of 104 unrelated natives of the Arabian Peninsula at high coverage, including 56 of indigenous Arab ancestry. The indigenous Arab genomes defined a cluster distinct from other ancestral groups, and these genomes showed clear hallmarks of an ancient out-of-Africa bottleneck. Similar to other Middle Eastern populations, the indigenous Arabs had higher levels of Neanderthal admixture compared to Africans but had lower levels than Europeans and Asians. These levels of Neanderthal admixture are consistent with an early divergence of Arab ancestors after the out-of-Africa bottleneck but before the major Neanderthal admixture events in Europe and other regions of Eurasia. When compared to worldwide populations sampled in the 1000 Genomes Project, although the indigenous Arabs had a signal of admixture with Europeans, they clustered in a basal, outgroup position to all 1000 Genomes non-Africans when considering pairwise similarity across the entire genome. These results place indigenous Arabs as the most distant relatives of all other contemporary non-Africans and identify these people as direct descendants of the first Eurasian populations established by the out-of-Africa migrations. © 2016 Rodriguez-Flores et al.; Published by Cold Spring Harbor Laboratory Press.

Activation Of Wild-Type Hras Suppresses The Earliest Stages Of Pancreatic Cancer.

PubMed

Weyandt, Jamie

2015-08-01

The RAS family of small GTPases is comprised of HRAS, NRAS, and KRAS. KRAS is invariably oncogenically mutated in pancreatic cancers, which is known to induce this disease. Beyond oncogenic KRAS, redox-dependent reactions have been implicated in the activation of the remaining wild-type RAS proteins in pancreatic cancer cell lines. These results suggest a possible involvement of wild-type RAS proteins in pancreatic cancer. To evaluate the impact of genetically suppressing wild-type RAS expression on pancreatic cancer. Hras homozygous null mice (Hras -/- ) were crossed into a Pdx-Cre; LSL-Kras G12D/+ (KC) murine background in which oncogenic Kras is activated in the pancreas to promote preinvasive pancreatic cancer. Tumor burden was then measured at different stages of disease. HRas -/- ;KC mice exhibited more precancerous lesions in the pancreas and more off-target skin papillomas compared to their wild-type counterparts, suggesting that Hras suppresses early oncogenic Kras-driven tumorigenesis, possibly at the time of initiation. Loss of Hras also reduced the survival of mice engineered to develop aggressive pancreatic cancer by the additional disruption of one allele of the tumor suppressor p53 (Trp53 R172H/+ ). However, this survival advantage was lost when both alleles of Trp53 were mutated, suggesting that wild-type Hras inhibits tumorigenesis in a p53-dependent fashion. Loss of wild-type Hras promotes the earliest stages of pancreatic tumorigenesis, and moreover results in more rapid progression of the disease. As such, mechanisms leading to activation of wild-type Ras proteins, including but not limited to redox-dependent reactions, may influence the development of pancreatic cancer. Copyright © 2015. Published by Elsevier B.V.

Development of a persistent chemical agent simulation system

NASA Technical Reports Server (NTRS)

1983-01-01

A Persistent Chemical Agent Simulation System was developed (PCASS) to simulate, for force-on-force training exercises, the field environment produced by the presence of persistent chemical agents. Such a simulant system must satisfy several requirements to be of value as a training aid. Specifically, it must provide for realistic training which will generate competency in at least the following areas: (1) detection of the persistent agent presence; (2) proper use of protective equipment and procedures; (3) determination of the extent of contamination; and (4) decontamination of equipment and personnel.

BDNF is essential to promote persistence of long-term memory storage

PubMed Central

Bekinschtein, Pedro; Cammarota, Martín; Katche, Cynthia; Slipczuk, Leandro; Rossato, Janine I.; Goldin, Andrea; Izquierdo, Ivan; Medina, Jorge H.

2008-01-01

Persistence is a characteristic attribute of long-term memories (LTMs). However, little is known about the molecular mechanisms that mediate this process. We recently showed that persistence of LTM requires a late protein synthesis- and BDNF-dependent phase in the hippocampus. Here, we show that intrahippocampal delivery of BDNF reverses the deficit in memory persistence caused by inhibition of hippocampal protein synthesis. Importantly, we demonstrate that BDNF induces memory persistence by itself, transforming a nonlasting LTM trace into a persistent one in an ERK-dependent manner. Thus, BDNF is not only necessary, but sufficient to induce a late postacquisition phase in the hippocampus essential for persistence of LTM storage. PMID:18263738

Nutrient transitions are a source of persisters in Escherichia coli biofilms.

PubMed

Amato, Stephanie M; Brynildsen, Mark P

2014-01-01

Chronic and recurrent infections have been attributed to persisters in biofilms, and despite this importance, the mechanisms of persister formation in biofilms remain unclear. The plethora of biofilm characteristics that could give rise to persisters, including slower growth, quorum signaling, oxidative stress, and nutrient heterogeneity, have complicated efforts to delineate formation pathways that generate persisters during biofilm development. Here we sought to specifically determine whether nutrient transitions, which are a common metabolic stress encountered within surface-attached communities, stimulate persister formation in biofilms and if so, to then identify the pathway. To accomplish this, we established an experimental methodology where nutrient availability to biofilm cells could be controlled exogenously, and then used that method to discover that diauxic carbon source transitions stimulated persister formation in Escherichia coli biofilms. Previously, we found that carbon source transitions stimulate persister formation in planktonic E. coli cultures, through a pathway that involved ppGpp and nucleoid-associated proteins, and therefore, tested the functionality of that pathway in biofilms. Biofilm persister formation was also found to be dependent on ppGpp and nucleoid-associated proteins, but the importance of specific proteins and enzymes between biofilm and planktonic lifestyles was significantly different. Data presented here support the increasingly appreciated role of ppGpp as a central mediator of bacterial persistence and demonstrate that nutrient transitions can be a source of persisters in biofilms.

On the causes of persistent apical periodontitis: a review.

PubMed

Nair, P N R

2006-04-01

Apical periodontitis is a chronic inflammatory disorder of periradicular tissues caused by aetiological agents of endodontic origin. Persistent apical periodontitis occurs when root canal treatment of apical periodontitis has not adequately eliminated intraradicular infection. Problems that lead to persistent apical periodontitis include: inadequate aseptic control, poor access cavity design, missed canals, inadequate instrumentation, debridement and leaking temporary or permanent restorations. Even when the most stringent procedures are followed, apical periodontitis may still persist as asymptomatic radiolucencies, because of the complexity of the root canal system formed by the main and accessory canals, their ramifications and anastomoses where residual infection can persist. Further, there are extraradicular factors -- located within the inflamed periapical tissue -- that can interfere with post-treatment healing of apical periodontitis. The causes of apical periodontitis persisting after root canal treatment have not been well characterized. During the 1990s, a series of investigations have shown that there are six biological factors that lead to asymptomatic radiolucencies persisting after root canal treatment. These are: (i) intraradicular infection persisting in the complex apical root canal system; (ii) extraradicular infection, generally in the form of periapical actinomycosis; (iii) extruded root canal filling or other exogenous materials that cause a foreign body reaction; (iv) accumulation of endogenous cholesterol crystals that irritate periapical tissues; (v) true cystic lesions, and (vi) scar tissue healing of the lesion. This article provides a comprehensive overview of the causative factors of non-resolving periapical lesions that are seen as asymptomatic radiolucencies post-treatment.

Persistence of Rift Valley fever virus in East Africa

NASA Astrophysics Data System (ADS)

Gachohi, J.; Hansen, F.; Bett, B.; Kitala, P.

2012-04-01

Rift Valley fever virus (RVFv) is a mosquito-borne pathogen of livestock, wildlife and humans that causes severe outbreaks in intervals of several years. One of the open questions is how the virus persists between outbreaks. We developed a spatially-explicit, individual-based simulation model of the RVFv transmission dynamics to investigate this question. The model, is based on livestock and mosquito population dynamics. Spatial aspects are explicitly represented by a set of grid cells that represent mosquito breeding sites. A grid cell measures 500 by 500m and the model considers a grid of 100 by 100 grid cells; the model thus operates on the regional scale of 2500km2. Livestock herds move between grid cells, and provide connectivity between the cells. The model is used to explore the spatio-temporal dynamics of RVFv persistence in absence of a wildlife reservoir in an east African semi-arid context. Specifically, the model assesses the importance of local virus persistence in mosquito breeding sites relative to global virus persistence mitigated by movement of hosts. Local persistence is determined by the length of time the virus remains in a mosquito breeding site once introduced. In the model, this is a function of the number of mosquitoes that emerge infected and their lifespan. Global persistence is determined by the level of connectivity between isolated grid cells. Our work gives insights into the ecological and epidemiological conditions under which RVFv persists. The implication for disease surveillance and management are discussed.

Persistent hydrogen bonding in polymorphic crystal structures.

PubMed

Galek, Peter T A; Fábián, László; Allen, Frank H

2009-02-01

The significance of hydrogen bonding and its variability in polymorphic crystal structures is explored using new automated structural analysis methods. The concept of a chemically equivalent hydrogen bond is defined, which may be identified in pairs of structures, revealing those types of bonds that may persist, or not, in moving from one polymorphic form to another. Their frequency and nature are investigated in 882 polymorphic structures from the Cambridge Structural Database. A new method to compare conformations of equivalent molecules is introduced and applied to derive distinct subsets of conformational and packing polymorphs. The roles of chemical functionality and hydrogen-bond geometry in persistent interactions are systematically explored. Detailed structural comparisons reveal a large majority of persistent hydrogen bonds that are energetically crucial to structural stability.

Persistent Structures in the Turbulent Boundary Layer

NASA Technical Reports Server (NTRS)

Palumbo, Dan; Chabalko, Chris

2005-01-01

Persistent structures in the turbulent boundary layer are located and analyzed. The data are taken from flight experiments on large commercial aircraft. An interval correlation technique is introduced which is able to locate the structures. The Morlet continuous wavelet is shown to not only locates persistent structures but has the added benefit that the pressure data are decomposed in time and frequency. To better understand how power is apportioned among these structures, a discrete Coiflet wavelet is used to decompose the pressure data into orthogonal frequency bands. Results indicate that some structures persist a great deal longer in the TBL than would be expected. These structure contain significant power and may be a primary source of vibration energy in the airframe.

Executive Functions and Prefrontal Cortex: A Matter of Persistence?

PubMed Central

Ball, Gareth; Stokes, Paul R.; Rhodes, Rebecca A.; Bose, Subrata K.; Rezek, Iead; Wink, Alle-Meije; Lord, Louis-David; Mehta, Mitul A.; Grasby, Paul M.; Turkheimer, Federico E.

2011-01-01

Executive function is thought to originates from the dynamics of frontal cortical networks. We examined the dynamic properties of the blood oxygen level dependent time-series measured with functional MRI (fMRI) within the prefrontal cortex (PFC) to test the hypothesis that temporally persistent neural activity underlies performance in three tasks of executive function. A numerical estimate of signal persistence, the Hurst exponent, postulated to represent the coherent firing of cortical networks, was determined and correlated with task performance. Increasing persistence in the lateral PFC was shown to correlate with improved performance during an n-back task. Conversely, we observed a correlation between persistence and increasing commission error – indicating a failure to inhibit a prepotent response – during a Go/No-Go task. We propose that persistence within the PFC reflects dynamic network formation and these findings underline the importance of frequency analysis of fMRI time-series in the study of executive functions. PMID:21286223

Pressure: the politechnics of water supply in Mumbai.

PubMed

Anand, Nikhil

2011-01-01

In Mumbai, most all residents are delivered their daily supply of water for a few hours every day, on a water supply schedule. Subject to a more precarious supply than the city's upper-class residents, the city's settlers have to consistently demand that their water come on “time” and with “pressure.” Taking pressure seriously as both a social and natural force, in this article I focus on the ways in which settlers mobilize the pressures of politics, pumps, and pipes to get water. I show how these practices not only allow settlers to live in the city, but also produce what I call hydraulic citizenship—a form of belonging to the city made by effective political and technical connections to the city's infrastructure. Yet, not all settlers are able to get water from the city water department. The outcomes of settlers' efforts to access water depend on a complex matrix of socionatural relations that settlers make with city engineers and their hydraulic infrastructure. I show how these arrangements describe and produce the cultural politics of water in Mumbai. By focusing on the ways in which residents in a predominantly Muslim settlement draw water despite the state's neglect, I conclude by pointing to the indeterminacy of water, and the ways in which its seepage and leakage make different kinds of politics and publics possible in the city.

Salt stress-induced transcription of σB- and CtsR-regulated genes in persistent and non-persistent Listeria monocytogenes strains from food processing plants.

PubMed

Ringus, Daina L; Ivy, Reid A; Wiedmann, Martin; Boor, Kathryn J

2012-03-01

Listeria monocytogenes is a foodborne pathogen that can persist in food processing environments. Six persistent and six non-persistent strains from fish processing plants and one persistent strain from a meat plant were selected to determine if expression of genes in the regulons of two stress response regulators, σ(B) and CtsR, under salt stress conditions is associated with the ability of L. monocytogenes to persist in food processing environments. Subtype data were also used to categorize the strains into genetic lineages I or II. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was used to measure transcript levels for two σ(B)-regulated genes, inlA and gadD3, and two CtsR-regulated genes, lmo1138 and clpB, before and after (t=10 min) salt shock (i.e., exposure of exponential phase cells to BHI+6% NaCl for 10 min at 37°C). Exposure to salt stress induced higher transcript levels relative to levels under non-stress conditions for all four stress and virulence genes across all wildtype strains tested. Analysis of variance (ANOVA) of induction data revealed that transcript levels for one gene (clpB) were induced at significantly higher levels in non-persistent strains compared to persistent strains (p=0.020; two-way ANOVA). Significantly higher transcript levels of gadD3 (p=0.024; two-way ANOVA) and clpB (p=0.053; two-way ANOVA) were observed after salt shock in lineage I strains compared to lineage II strains. No clear association between stress gene transcript levels and persistence was detected. Our data are consistent with an emerging model that proposes that establishment of L. monocytogenes persistence in a specific environment occurs as a random, stochastic event, rather than as a consequence of specific bacterial strain characteristics.

Persistence length of collagen molecules based on nonlocal viscoelastic model.

PubMed

Ghavanloo, Esmaeal

2017-12-01

Persistence length is one of the most interesting properties of a molecular chain, which is used to describe the stiffness of a molecule. The experimentally measured values of the persistence length of the collagen molecule are widely scattered from 14 to 180 nm. Therefore, an alternative approach is highly desirable to predict the persistence length of a molecule and also to explain the experimental results. In this paper, a nonlocal viscoelastic model is developed to obtain the persistence length of the collagen molecules in solvent. A new explicit formula is proposed for the persistence length of the molecule with the consideration of the small-scale effect, viscoelastic properties of the molecule, loading frequency, and viscosity of the solvent. The presented model indicates that there exists a range of molecule lengths in which the persistence length strongly depends on the frequency and spatial mode of applied loads, small-scale effect, and viscoelastic properties of the collagen.

Persistence of environmental DNA in freshwater ecosystems.

PubMed

Dejean, Tony; Valentini, Alice; Duparc, Antoine; Pellier-Cuit, Stéphanie; Pompanon, François; Taberlet, Pierre; Miaud, Claude

2011-01-01

The precise knowledge of species distribution is a key step in conservation biology. However, species detection can be extremely difficult in many environments, specific life stages and in populations at very low density. The aim of this study was to improve the knowledge on DNA persistence in water in order to confirm the presence of the focus species in freshwater ecosystems. Aquatic vertebrates (fish: Siberian sturgeon and amphibian: Bullfrog tadpoles) were used as target species. In control conditions (tanks) and in the field (ponds), the DNA detectability decreases with time after the removal of the species source of DNA. DNA was detectable for less than one month in both conditions. The density of individuals also influences the dynamics of DNA detectability in water samples. The dynamics of detectability reflects the persistence of DNA fragments in freshwater ecosystems. The short time persistence of detectable amounts of DNA opens perspectives in conservation biology, by allowing access to the presence or absence of species e.g. rare, secretive, potentially invasive, or at low density. This knowledge of DNA persistence will greatly influence planning of biodiversity inventories and biosecurity surveys.

New daily persistent headache.

PubMed

Evans, Randolph W

2003-08-01

New daily persistent headache (NDPH), which is the acute onset of headache within 3 days and is persistent for 15 days or more each month for at least 3 months, is a predominantly female heterogeneous subtype of chronic daily headache, typically with migraine features of unknown etiology. NDPH may be a presentation of other primary headaches such as new onset migraine, tension, or benign thunderclap headache. The headaches can be difficult to treat. The diagnosis is one of excluding the many secondary types or NDPH mimics, which is especially critical early in the course of the disease when a secondary etiology is more likely. NDPH mimics include postmeningitis headache, NDPH with medication rebound, neoplasms, temporal arteritis, chronic meningitis, chronic subdural hematoma, post-traumatic headaches, sphenoid sinusitis, hypertension, subarachnoid hemorrhage, low cerebrospinal fluid pressure syndrome, cervical artery dissections, pseudotumor cerebri without papilledema, and cerebral venous thrombosis.

Energy Savings Lifetimes and Persistence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoffman, Ian M.; Schiller, Steven R.; Todd, Annika

2016-02-01

This technical brief explains the concepts of energy savings lifetimes and savings persistence and discusses how program administrators use these factors to calculate savings for efficiency measures, programs and portfolios. Savings lifetime is the length of time that one or more energy efficiency measures or activities save energy, and savings persistence is the change in savings throughout the functional life of a given efficiency measure or activity. Savings lifetimes are essential for assessing the lifecycle benefits and cost effectiveness of efficiency activities and for forecasting loads in resource planning. The brief also provides estimates of savings lifetimes derived from amore » national collection of costs and savings for electric efficiency programs and portfolios.« less

An Alternative Model for the Early Peopling of Southern South America Revealed by Analyses of Three Mitochondrial DNA Haplogroups

PubMed Central

de Saint Pierre, Michelle; Bravi, Claudio M.; Motti, Josefina M. B.; Fuku, Noriyuki; Tanaka, Masashi; Llop, Elena; Bonatto, Sandro L.; Moraga, Mauricio

2012-01-01

After several years of research, there is now a consensus that America was populated from Asia through Beringia, probably at the end of the Pleistocene. But many details such as the timing, route(s), and origin of the first settlers remain uncertain. In the last decade genetic evidence has taken on a major role in elucidating the peopling of the Americas. To study the early peopling of South America, we sequenced the control region of mitochondrial DNA from 300 individuals belonging to indigenous populations of Chile and Argentina, and also obtained seven complete mitochondrial DNA sequences. We identified two novel mtDNA monophyletic clades, preliminarily designated B2l and C1b13, which together with the recently described D1g sub-haplogroup have locally high frequencies and are basically restricted to populations from the extreme south of South America. The estimated ages of D1g and B2l, about ∼15,000 years BP, together with their similar population dynamics and the high haplotype diversity shown by the networks, suggests that they probably appeared soon after the arrival of the first settlers and agrees with the dating of the earliest archaeological sites in South America (Monte Verde, Chile, 14,500 BP). One further sub-haplogroup, D4h3a5, appears to be restricted to Fuegian-Patagonian populations and reinforces our hypothesis of the continuity of the current Patagonian populations with the initial founders. Our results indicate that the extant native populations inhabiting South Chile and Argentina are a group which had a common origin, and suggest a population break between the extreme south of South America and the more northern part of the continent. Thus the early colonization process was not just an expansion from north to south, but also included movements across the Andes. PMID:22970129

An alternative model for the early peopling of southern South America revealed by analyses of three mitochondrial DNA haplogroups.

PubMed

de Saint Pierre, Michelle; Bravi, Claudio M; Motti, Josefina M B; Fuku, Noriyuki; Tanaka, Masashi; Llop, Elena; Bonatto, Sandro L; Moraga, Mauricio

2012-01-01

After several years of research, there is now a consensus that America was populated from Asia through Beringia, probably at the end of the Pleistocene. But many details such as the timing, route(s), and origin of the first settlers remain uncertain. In the last decade genetic evidence has taken on a major role in elucidating the peopling of the Americas. To study the early peopling of South America, we sequenced the control region of mitochondrial DNA from 300 individuals belonging to indigenous populations of Chile and Argentina, and also obtained seven complete mitochondrial DNA sequences. We identified two novel mtDNA monophyletic clades, preliminarily designated B2l and C1b13, which together with the recently described D1g sub-haplogroup have locally high frequencies and are basically restricted to populations from the extreme south of South America. The estimated ages of D1g and B2l, about ~15,000 years BP, together with their similar population dynamics and the high haplotype diversity shown by the networks, suggests that they probably appeared soon after the arrival of the first settlers and agrees with the dating of the earliest archaeological sites in South America (Monte Verde, Chile, 14,500 BP). One further sub-haplogroup, D4h3a5, appears to be restricted to Fuegian-Patagonian populations and reinforces our hypothesis of the continuity of the current Patagonian populations with the initial founders. Our results indicate that the extant native populations inhabiting South Chile and Argentina are a group which had a common origin, and suggest a population break between the extreme south of South America and the more northern part of the continent. Thus the early colonization process was not just an expansion from north to south, but also included movements across the Andes.

The Enigmatic Persistence of Anorexia Nervosa

PubMed Central

Walsh, B. Timothy

2014-01-01

Objective In this review, based on recent advances in cognitive neuroscience, the author presents a formulation in which the marked persistence of anorexia nervosa can be usefully understood as a well-ingrained maladaptive habit. Method The author reviewed the relevant literature on the development and course of anorexia nervosa and interpreted critical features in light of developments in cognitive neuroscience. Results Anorexia nervosa is a well characterized disorder with remarkable persistence both across history and among affected individuals. Food restriction, the salient behavioral feature of the disorder, often begins innocently but gradually takes on a life of its own. Over time, it becomes highly entrenched and resistant to change through either psychological or pharmacological treatment. Cognitive neuroscience has described two related but distinct processes that underlie the acquisition of new patterns of behavior, namely, action-outcome and stimulus-response learning. It is likely that both processes are engaged in the development of anorexia nervosa and that stimulus-response learning (that is, habit formation) is critical to the persistence of the dieting behavior. Conclusions The formulation of the dieting behavior characteristic of anorexia nervosa as a well-entrenched habit provides a basis for understanding the striking persistence of this disorder. This model helps explain the resistance of anorexia nervosa to interventions that have established efficacy in related disorders and implies that addressing the dieting behavior is critical, especially early in the course of the illness, before it has become ingrained. PMID:23429750

Extending and implementing the Persistent ID pillars

NASA Astrophysics Data System (ADS)

Car, Nicholas; Golodoniuc, Pavel; Klump, Jens

2017-04-01

The recent double decade anniversary of scholarly persistent identifier use has triggered journal special editions such as "20 Years of Persistent Identifiers". For such a publication, it is apt to consider the longevity of some persistent identifier (PID) mechanisms (Digital Object Identifiers) and the partial disappearance of others (Life Sciences IDs). We have previously postulated a set of "PID Pillars" [1] which are design principles aimed at ensuring PIDs can survive technology and social change and thus persist for the long term that we have drawn from our observations of PIDs at work over many years. The principles: describe how to ensure identifiers' system and organisation independence; codify the delivery of essential PID system functions; mandate a separation of PID functions from data delivery mechanisms; and require generation of policies detailing how change is handled. In this presentation, first we extend on our previous work of introducing the pillars by refining their descriptions, giving specific suggestions for each and presenting some work that addresses them. Second, we propose a baseline data model for persistent identifiers that, if used, would assist the separation of PID metadata and PID system functioning. This would allow PID system function specifics to change over time (e.g. resolver services or even resolution protocols) and yet preserve the PIDs themselves. Third, we detail our existing PID system — the PID Service [2] — that partially implements the pillars and describe both its successes and shortcomings. Finally, we describe our planned next-generation system that will aim to use the baseline data model and fully implement the pillars.

Post-infectious persistent cough: pathogenesis and therapeutic options.

PubMed

Capristo, Carlo; Rossi, Giovanni A

2017-10-01

Post-infectious cough is a common symptom associated with common colds and/or upper respiratory tract infection. This cough is expected to last for only for few days and resolve spontaneously, whilst when persists for longer than three weeks is defined "persistent" and is associated tickling or an irritating sensation in the throat which often leads to paroxysms of coughing. Persistent post-infectious cough can cause morbidity since it may interfere with usual living. Despite the recent advances in understanding the mechanisms that regulate cough, in physiological and pathological conditions, current therapeutic options for post-infectious cough are little or only moderately effective.

Multiresolution persistent homology for excessively large biomolecular datasets

NASA Astrophysics Data System (ADS)

Xia, Kelin; Zhao, Zhixiong; Wei, Guo-Wei

2015-10-01

Although persistent homology has emerged as a promising tool for the topological simplification of complex data, it is computationally intractable for large datasets. We introduce multiresolution persistent homology to handle excessively large datasets. We match the resolution with the scale of interest so as to represent large scale datasets with appropriate resolution. We utilize flexibility-rigidity index to access the topological connectivity of the data set and define a rigidity density for the filtration analysis. By appropriately tuning the resolution of the rigidity density, we are able to focus the topological lens on the scale of interest. The proposed multiresolution topological analysis is validated by a hexagonal fractal image which has three distinct scales. We further demonstrate the proposed method for extracting topological fingerprints from DNA molecules. In particular, the topological persistence of a virus capsid with 273 780 atoms is successfully analyzed which would otherwise be inaccessible to the normal point cloud method and unreliable by using coarse-grained multiscale persistent homology. The proposed method has also been successfully applied to the protein domain classification, which is the first time that persistent homology is used for practical protein domain analysis, to our knowledge. The proposed multiresolution topological method has potential applications in arbitrary data sets, such as social networks, biological networks, and graphs.

Persistence of deep-tendon reflexes during partial cataplexy.

PubMed

Barateau, Lucie; Pizza, Fabio; Lopez, Régis; Antelmi, Elena; Plazzi, Giuseppe; Dauvilliers, Yves

2018-05-01

Deep-tendon reflexes are abolished during generalized cataplexy, but whether this is the case in partial cataplexy currently remains unknown. Partial cataplexy may mimic other neurologic/psychiatric phenomena, and knowledge of the reflexes status may provide information for differential diagnosis. We assessed whether deep-tendon reflexes are persistent during partial cataplexy. Five drug-free patients with typical diagnoses of narcolepsy and clear-cut partial cataplexy were diagnosed in Reference Narcolepsy Centers in France and Italy. Biceps and patellar reflexes were elicited by physicians in charge and video-documented during cataplexy. Reflexes were assessed several times for each patient in different conditions and for various localizations of cataplexy. The absence of tendon reflexes and complete loss of muscle tone during generalized cataplexy was confirmed, but the persistence of those reflexes during several partial cataplectic attacks at different ages, gender, localization of cataplexy (upper limbs, face) and reflexes (biceps, patellar) in drug-naive or withdrawal conditions was documented. The persistence of tendon reflexes during several partial cataplexy episodes contrasts with their absence during generalized cataplexy. This discovery has clinical implications: the persistence of tendon reflexes does not rule out cataplexy diagnosis for partial attacks, whereas their transient abolishment or persistence during generalized attacks indicates cataplexy or pseudocataplexy, respectively. Copyright © 2018. Published by Elsevier B.V.

Hyperthyroidism as a cause of persistent vomiting.

PubMed

Hoogendoorn, E H; Cools, B M

2004-09-01

A 32-year-old woman presented with persistent vomiting, epigastric pain and weight loss. A sinus tachycardia was the clue to the diagnosis of hyperthyroidism due to Graves' disease. On treatment with propylthiouracil and a beta-blocking agent, her symptoms resolved within one day, even though her free thyroxine level was still high. Hyperthyroidism is an uncommon, but previously reported cause of persistent vomiting.

Statistic versus stochastic characterization of persistent droughts

NASA Astrophysics Data System (ADS)

Gonzalez-Perez, J.; Valdes, J. B.

2005-12-01

Droughts are one of more devastating natural disasters. A drought event is always related with deficiency in precipitation over a time period. As longer are the drought periods, larger are the damages associated with, following a potential relationship. Additionally, the extension covered by an event also increases its impact, because it makes difficult to compensate the deficit from neighbourhood water resources. Therefore, the characterization of a drought by its persistent deficit, and the area over which it extends are main points to be carried on. The Standardized Precipitation Index (SPI) provides a statistical characterization of the deficits. Its computation, for different aggregation time scales, allows a persistence evaluation. Another more recent statistic that may be applied in drought characterization is the extreme persistent probability function (e.p.f.), which characterizes the persistence of extreme realizations in a random sequence. This work presents an analysis of the differences in performance of the SPI and the e.p.f. in the statistical characterization of a drought event. The inclusion of the persistency directly in the statistic gives to the e.p.f. an advantage over the SPI. Furthermore, the relationship between the e.p.f. and its mean frequency of recurrence is known. Thus, the e.p.f. may be applied to provide either statistic or stochastic characterization of a drought event. Both criteria were compared, showing that the stochastic characterization produces a better drought indicator. The stochastic characterization using the e.p.f. as a criterion yields the new Drought Frequency Index (DFI). The index is applicable to any random water related variable to identify drought events. Its main advantages over the SPI are the direct inclusion of persistence, and its larger robustness to the time scale. To incorporate the spatial extension in the characterization of a drought event, the new DFI may also be evaluated to characterize the drought

What Makes Them Stay? A Study of Nursing Faculty Persistence

ERIC Educational Resources Information Center

Greer, Tiffany D.

2017-01-01

There is a nursing faculty shortage contributing to the nursing shortage that necessitates more than just standard recruitment and retention efforts. The purpose of this study was to understand faculty persistence by asking nurse faculty members why they persist in their educating role, what factors influence their persistence, and what obstacles…

Trauma and autobiographical memory: contents and determinants of earliest memories among war-affected Palestinian children.

PubMed

Peltonen, Kirsi; Kangaslampi, Samuli; Qouta, Samir; Punamäki, Raija-Leena

2017-11-01

The contents of earliest memories (EM), as part of autobiographical memory, continue to fascinate scientists and therapists. However, research is scarce on the determinants of EM, especially among children. This study aims, first, to identify contents of EM of children living in war conditions, and, second, to analyse child gender, traumatic events and mental health as determinants of the contents of EM. The participants were 240 Palestinian schoolchildren from the Gaza Strip (10-12 years, M = 11.35, SD = 0.57; 49.4% girls). They responded to an open-ended EM question, and reported their trauma exposures (war trauma, losses and current traumatic events), posttraumatic stress, depressive symptoms and psychosocial well-being, indicating mental health. The EM coding involved nature, social orientation, emotional tone and specificity. Results showed, first, that 43% reported playing or visiting a nice place as EM, and about a third (30%) traumatic events or accidents (30%) or miscellaneous events (27%). The individual and social orientation were almost equally common, the emotional tone mainly neutral (45.5%), and 60% remembered a specific event. Second, boys remembered more EM involving traumatic events or accidents, and girls more social events. Third, war trauma was associated with less positive emotional tone and with more specific memories.

Multiscale Persistent Functions for Biomolecular Structure Characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xia, Kelin; Li, Zhiming; Mu, Lin

Here in this paper, we introduce multiscale persistent functions for biomolecular structure characterization. The essential idea is to combine our multiscale rigidity functions (MRFs) with persistent homology analysis, so as to construct a series of multiscale persistent functions, particularly multiscale persistent entropies, for structure characterization. To clarify the fundamental idea of our method, the multiscale persistent entropy (MPE) model is discussed in great detail. Mathematically, unlike the previous persistent entropy (Chintakunta et al. in Pattern Recognit 48(2):391–401, 2015; Merelli et al. in Entropy 17(10):6872–6892, 2015; Rucco et al. in: Proceedings of ECCS 2014, Springer, pp 117–128, 2016), a special resolutionmore » parameter is incorporated into our model. Various scales can be achieved by tuning its value. Physically, our MPE can be used in conformational entropy evaluation. More specifically, it is found that our method incorporates in it a natural classification scheme. This is achieved through a density filtration of an MRF built from angular distributions. To further validate our model, a systematical comparison with the traditional entropy evaluation model is done. Additionally, it is found that our model is able to preserve the intrinsic topological features of biomolecular data much better than traditional approaches, particularly for resolutions in the intermediate range. Moreover, by comparing with traditional entropies from various grid sizes, bond angle-based methods and a persistent homology-based support vector machine method (Cang et al. in Mol Based Math Biol 3:140–162, 2015), we find that our MPE method gives the best results in terms of average true positive rate in a classic protein structure classification test. More interestingly, all-alpha and all-beta protein classes can be clearly separated from each other with zero error only in our model. Finally, a special protein structure index (PSI) is proposed, for

Admixture patterns and genetic differentiation in negrito groups from West Malaysia estimated from genome-wide SNP data.

PubMed

Jinam, Timothy A; Phipps, Maude E; Saitou, Naruya

2013-01-01

Southeast Asia houses various culturally and linguistically diverse ethnic groups. In Malaysia, where the Malay, Chinese, and Indian ethnic groups form the majority, there exist minority groups such as the "negritos" who are believed to be descendants of the earliest settlers of Southeast Asia. Here we report patterns of genetic substructure and admixture in two Malaysian negrito populations (Jehai and Kensiu), using ~50,000 genome-wide single-nucleotide polymorphism (SNP) data. We found traces of recent admixture in both the negrito populations, particularly in the Jehai, with the Malay through principal component analysis and STRUCTURE analysis software, which suggested that the admixture was as recent as one generation ago. We also identified significantly differentiated nonsynonymous SNPs and haplotype blocks related to intracellular transport, metabolic processes, and detection of stimulus. These results highlight the different levels of admixture experienced by the two Malaysian negritos. Delineating admixture and differentiated genomic regions should be of importance in designing and interpretation of molecular anthropology and disease association studies. Copyright © 2013 Wayne State University Press, Detroit, Michigan 48201-1309.

Earliest isotopic evidence in the Maya region for animal management and long-distance trade at the site of Ceibal, Guatemala.

PubMed

Sharpe, Ashley E; Emery, Kitty F; Inomata, Takeshi; Triadan, Daniela; Kamenov, George D; Krigbaum, John

2018-04-03

This study uses a multiisotope (carbon, nitrogen, oxygen, and strontium) approach to examine early animal management in the Maya region. An analysis of faunal specimens across almost 2,000 years (1000 BC to AD 950) at the site of Ceibal, Guatemala, reveals the earliest evidence for live-traded dogs and possible captive-reared taxa in the Americas. These animals may have been procured for ceremonial functions based on their location in the monumental site core, suggesting that animal management and trade began in the Maya area to promote special events, activities that were critical in the development of state society. Isotopic evidence for animal captivity at Ceibal reveals that animal management played a greater role in Maya communities than previously believed. Copyright © 2018 the Author(s). Published by PNAS.

Cortical dynamics of feature binding and reset: control of visual persistence.

PubMed

Francis, G; Grossberg, S; Mingolla, E

1994-04-01

An analysis of the reset of visual cortical circuits responsible for the binding or segmentation of visual features into coherent visual forms yields a model that explains properties of visual persistence. The reset mechanisms prevent massive smearing of visual percepts in response to rapidly moving images. The model simulates relationships among psychophysical data showing inverse relations of persistence to flash luminance and duration, greater persistence of illusory contours than real contours, a U-shaped temporal function for persistence of illusory contours, a reduction of persistence due to adaptation with a stimulus of like orientation, an increase of persistence with spatial separation of a masking stimulus. The model suggests that a combination of habituative, opponent, and endstopping mechanisms prevent smearing and limit persistence. Earlier work with the model has analyzed data about boundary formation, texture segregation, shape-from-shading, and figure-ground separation. Thus, several types of data support each model mechanism and new predictions are made.

Persistent frenulum of the epiglottis in four foals.

PubMed

Yarbrough, T B; Voss, E; Herrgesell, E J; Shaw, M

1999-01-01

To report the clinical signs and management of 4 foals with persistent frenulum of the epiglottis. Case report. Four newborn foals. Foals were admitted with a complaint of oronasal reflux after nursing. Variable systemic signs of aspiration pneumonia were evident. Nasal endoscopy confirmed persistent dorsal displacement of the soft palate. Persistent frenulum of the epiglottis, confirmed by oral endoscopic examination, was transected. After surgery, all foals had the epiglottis positioned normally, dorsal to the soft palate. Clinical signs of oronasal reflux resolved by the second nursing attempt in 3 foals, whereas this was difficult to assess in one foal that was nursed intermittently because of the mares behavior. This foal died 2 days later. The other 3 foals have had normal epiglottic function for 2-4 years. Persistent frenulum of the epiglottis should be considered in foals with oronasal reflux from birth. With appropriate medical and surgical management the prognosis for resolution should be good.

Estimating Carcass Persistence and Scavenging Bias in a Human Influenced Landscape

USGS Publications Warehouse

Flint, Paul L.; Lance, Ellen W.; Sowl, Kristine M.; Donnelly, Tyrone F.

2010-01-01

We examined variation in persistence rates of waterfowl carcasses placed along a series of transects in tundra habitats in western Alaska. This study was designed to assess the effects of existing tower structures and was replicated with separate trials in winter, summer and fall as both the resident avian population and the suite of potential scavengers varied seasonally. Carcass persistence rates were uniformly low, with <50% of carcasses persisting for more than a day on average. Persistence rate varied by carcass age, carcass size, among transects and was lowest in the fall and highest in the summer. We found little support for models where persistence varied in relation to the presence of tower structures. We interpret this as evidence that scavengers were not habituated to searching for carcasses near these structures. Our data demonstrate that only a small fraction of bird carcasses are likely to persist between searches, and if not appropriately accounted for, scavenging bias could significantly influence bird mortality estimates. The variation that we documented suggests that persistence rates should not be extrapolated among tower locations or across time periods as the variation in carcass persistence will result in biased estimates of total bird strike mortality.

Biannual birth pulses allow filoviruses to persist in bat populations

PubMed Central

Hayman, David T. S.

2015-01-01

Filoviruses Ebolavirus (EBOV) and Marburgvirus (MARV) cause haemorrhagic fevers with high mortality rates, posing significant threats to public health. To understand transmission into human populations, filovirus dynamics within reservoir host populations must be understood. Studies have directly linked filoviruses to bats, but the mechanisms allowing viral persistence within bat populations are poorly understood. Theory suggests seasonal birthing may decrease the probability of pathogen persistence within populations, but data suggest MARV may persist within colonies of seasonally breeding Egyptian fruit bats, Rousettus aegyptiacus. I synthesize available filovirus and bat data in a stochastic compartmental model to explore fundamental questions relating to filovirus ecology: can filoviruses persist within isolated bat colonies; do critical community sizes exist; and how do host–pathogen relationships affect spillover transmission potential? Synchronous annual breeding and shorter incubation periods did not allow filovirus persistence, whereas bi-annual breeding and longer incubation periods, such as reported for Egyptian fruit bats and EBOV in experimental studies, allowed persistence in colony sizes often found in nature. Serological data support the findings, with bats from species with two annual birth pulses more likely to be seropositive (odds ratio (OR) 4.4, 95% confidence interval (CI) 2.5–8.7) than those with one, suggesting that biannual birthing is necessary for filovirus persistence. PMID:25673678

Psychological factors predicting the distress to female persistent genital arousal symptoms.

PubMed

Carvalho, Joana; Veríssimo, Ana; Nobre, Pedro J

2015-01-01

Symptoms of persistent genital arousal are expected to negatively affect women's sexual and emotional well-being. However, not all women who experience persistent genital arousal complain about their genital condition. Against this background, this study aimed to evaluate psychological predictors of the distress associated with persistent genital arousal symptoms, as well as psychological moderators influencing the conditions under which persistent genital arousal causes distress. A total of 117 women reporting symptoms of persistent genital arousal answered to online questionnaires measuring personality traits, sexual beliefs, and dyadic adjustment. Women have also completed a checklist measuring the frequency/severity of persistent genital arousal symptoms and the distress/impairment caused by these symptoms. Results showed that neuroticism, (low) openness, sexual conservatism, and (low) dyadic adjustment significantly predicted distress associated with genital symptoms. Furthermore, sexual conservatism was found to moderate the relation between the symptoms' severity and the distress associated with those symptoms. Overall, sexual conservatism seems to be a key differentiator factor, influencing the psychological conditions under which women may report higher levels of distress caused by persistent genital arousal. Because such findings focus on the distress to genital arousal symptoms rather than on persistent genital arousal disorder as a clinical entity, the results under consideration may or may not characterize women formally assigned to the persistent genital arousal disorder label.

Student Persistence Predictors and Community College Institutional Effectiveness

ERIC Educational Resources Information Center

Shelley, Jeffrey Lee

2013-01-01

The purpose of this study was to expand the literature on student persistence in community colleges through three research innovations. First, the literature on student persistence in community colleges was expanded by applying theory to the identification and testing of predictors. Second, it was expanded by validating retention prediction…

Supporting Academic Persistence in Low-Skilled Adult Learners

ERIC Educational Resources Information Center

O'Neill, Susan; Thomson, Margareta Maria

2013-01-01

The current literature review explores the factors that contribute to academic persistence for adult learners. The aim of the study is to identify current research-based strategies aimed at supporting learner persistence, particularly for low-skilled adults. Elements of three theoretical frameworks, namely, expectancy-value theory (EVT), goal…

Access & Persistence. Summer 2008

ERIC Educational Resources Information Center

Advisory Committee on Student Financial Assistance, 2008

2008-01-01

This issue of "Access & Persistence" describes the roundtable discussion, "Ensuring Access to College Amid Economic Uncertainty," held on June 13, 2008 in Nashville, Tennessee. The purpose of the discussion was to gather information from a variety of perspectives within the higher education community on effects of the…

Neural processes underlying cultural differences in cognitive persistence.

PubMed

Telzer, Eva H; Qu, Yang; Lin, Lynda C

2017-08-01

Self-improvement motivation, which occurs when individuals seek to improve upon their competence by gaining new knowledge and improving upon their skills, is critical for cognitive, social, and educational adjustment. While many studies have delineated the neural mechanisms supporting extrinsic motivation induced by monetary rewards, less work has examined the neural processes that support intrinsically motivated behaviors, such as self-improvement motivation. Because cultural groups traditionally vary in terms of their self-improvement motivation, we examined cultural differences in the behavioral and neural processes underlying motivated behaviors during cognitive persistence in the absence of extrinsic rewards. In Study 1, 71 American (47 females, M=19.68 years) and 68 Chinese (38 females, M=19.37 years) students completed a behavioral cognitive control task that required cognitive persistence across time. In Study 2, 14 American and 15 Chinese students completed the same cognitive persistence task during an fMRI scan. Across both studies, American students showed significant declines in cognitive performance across time, whereas Chinese participants demonstrated effective cognitive persistence. These behavioral effects were explained by cultural differences in self-improvement motivation and paralleled by increasing activation and functional coupling between the inferior frontal gyrus (IFG) and ventral striatum (VS) across the task among Chinese participants, neural activation and coupling that remained low in American participants. These findings suggest a potential neural mechanism by which the VS and IFG work in concert to promote cognitive persistence in the absence of extrinsic rewards. Thus, frontostriatal circuitry may be a neurobiological signal representing intrinsic motivation for self-improvement that serves an adaptive function, increasing Chinese students' motivation to engage in cognitive persistence. Copyright © 2017 Elsevier Inc. All rights

Demonstration of persistent contamination of a cooked egg product production facility with Salmonella enterica serovar Tennessee and characterization of the persistent strain.

PubMed

Jakočiūnė, D; Bisgaard, M; Pedersen, K; Olsen, J E

2014-08-01

The aim of this study was to investigate whether continuous contamination of light pasteurized egg products with Salmonella enterica serovar Tennessee (S. Tennessee) at a large European producer of industrial egg products was caused by persistent contamination of the production facility and to characterize the persistent strains. Seventy-three S. Tennessee isolates collected from products over a 3-year period with intermittent contamination, and 15 control strains were compared by pulsed field gel electrophoresis (PFGE) using two enzymes. Forty-five case isolates distributed throughout the full period were shown to belong to one profile type. Isolates representing different PFGE profiles were all assigned to ST 319 by multilocus sequence typing (MLST). The case isolates did not show a higher ability to form biofilm on a plastic surface than noncase isolates. Characteristically, members of the persistent clone were weak producers of H2 S in laboratory medium. S. Tennessee isolated from the case was able to grow better in pasteurized egg product compared with other serovars investigated. It was concluded that the contamination was caused by a persistent strain in the production facility and that this strain apparently had adapted to grow in the relevant egg product. S. Tennessee has previously been associated with persistence in hatching facilities. This is the first report of persistent contamination of an egg production facility with this serovar. © 2014 The Society for Applied Microbiology.

Overcoming Persistent Poverty--and Sinking into It. Income Trends in Persistent-Poverty and Other High-Poverty Rural Counties, 1989-94.

ERIC Educational Resources Information Center

Nord, Mark

In 1989, 31.6 percent of the rural poor lived in persistent-poverty counties (those with poverty rates exceeding 20 percent for every decennial census year since 1960), and an additional 12.6 percent lived in "new" high-poverty counties. While this represents less than half the rural poor, high and persistent poverty is of particular…

Lactase Non-persistence and Lactose Intolerance.

PubMed

Bayless, Theodore M; Brown, Elizabeth; Paige, David M

2017-05-01

To evaluate the clinical and nutritional significance of genetically determined lactase non-persistence and potential lactose and milk intolerance in 65-70% of the world's adult population. Milk consumption is decreasing in the USA and is the lowest in countries with a high prevalence of lactase non-persistence. The dairy industry and Minnesota investigators have made efforts to minimize the influence of lactose intolerance on milk consumption. Some lactose intolerant individuals, without co-existent irritable bowel syndrome, are able to consume a glass of milk with a meal with no or minor symptoms. The high frequency of lactase persistence in offspring of Northern European countries and in some nomadic African tribes is due to mutations in the promoter of the lactase gene in association with survival advantage of milk drinking. Educational and commercial efforts to improve calcium and Vitamin D intake have focused on urging consumption of tolerable amounts of milk with a meal, use of lowered lactose-content foods including hard cheeses, yogurt, and lactose-hydrolyzed milk products.

Persistent delirium in older hospital patients.

PubMed

Cole, Martin G

2010-05-01

There are two contradictory views on the prognosis of delirium in older hospital patients. On one hand, the Diagnostic and Statistical Manual, 4th Text Revision (DSM-IV-TR), describes delirium as a transient cognitive disorder, the majority of affected individuals having a full recovery. On the other hand, longitudinal studies of delirium in this population report that the outcomes are poor. This review proposes to reconcile these two contradictory views. In older hospital patients, delirium appears to persist in 44.7% of patients at discharge and in 32.8, 25.6 and 21% of patients at 1, 3 and 6 months, respectively. The outcomes (cognition, function, nursing home placement, mortality) of patients with persistent delirium are consistently worse than the outcomes of patients who recover from delirium. The majority of older hospital patients with delirium may recover but the persistence of delirium in a substantial minority of patients may account, in large part, for the poor outcomes of delirium in this population. This proposal has potentially important implications for clinical practice and research.

Persistant dysphonia following endotracheal intubation.

PubMed

Hamdan, Abdul-Latif; Sabra, Omar; Rameh, Charbel; El-Khatib, Mohamad

2007-02-01

Voice production is a complex process that involves more than one system, yet most causes of dysphonia are attributed to disturbances in the laryngeal structures and little attention is paid to extralaryngeal factors. Persistent dysphonia after general anesthesia is a challenge to both anesthesiologists and otolaryngologists. The etiology is often multivariable and necessitates a team approach for proper diagnosis. Laryngeal symptoms are subdivided into phonatory disturbances and airway related complaints. When they become persistent for more than 72 hours or are coupled with airway symptoms such as hemoptysis, stridor, dyspnea or aspiration, the anesthesiologist should suspect injury to the vocal folds or cricoarytenoid joints. Here-below, the laryngeal manifestations of endotracheal intubation and the pathophysiology of vocal fold scarring are discussed.

Adolescents' experience of complex persistent pain.

PubMed

Sørensen, Kari; Christiansen, Bjørg

2017-04-01

Persistent (chronic) pain is a common phenomenon in adolescents. When young people are referred to a pain clinic, they usually have amplified pain signals, with pain syndromes of unconfirmed ethology, such as fibromyalgia and complex regional pain syndrome (CRPS). Pain is complex and seems to be related to a combination of illness, injury, psychological distress, and environmental factors. These young people are found to have higher levels of distress, anxiety, sleep disturbance, and lower mood than their peers and may be in danger of entering adulthood with mental and physical problems. In order to understand the complexity of persistent pain in adolescents, there seems to be a need for further qualitative research into their lived experiences. The aim of this study was to explore adolescents' experiences of complex persistent pain and its impact on everyday life. The study has an exploratory design with individual in-depth interviews with six youths aged 12-19, recruited from a pain clinic at a main referral hospital in Norway. A narrative approach allowed the informants to give voice to their experiences concerning complex persistent pain. A hermeneutic analysis was used, where the research question was the basis for a reflective interpretation. Three main themes were identified: (1) a life with pain and unpleasant bodily expressions; (2) an altered emotional wellbeing; and (3) the struggle to keep up with everyday life. The pain was experienced as extremely strong, emerging from a minor injury or without any obvious causation, and not always being recognised by healthcare providers. The pain intensity increased as the suffering got worse, and the sensation was hard to describe with words. Parts of their body could change in appearance, and some described having pain-attacks or fainting. The feeling of anxiety was strongly connected to the pain. Despair and uncertainty contributed to physical disability, major sleep problems, school absence, and withdrawal from

Persistence length measurements from stochastic single-microtubule trajectories.

PubMed

van den Heuvel, M G L; Bolhuis, S; Dekker, C

2007-10-01

We present a simple method to determine the persistence length of short submicrometer microtubule ends from their stochastic trajectories on kinesin-coated surfaces. The tangent angle of a microtubule trajectory is similar to a random walk, which is solely determined by the stiffness of the leading tip and the velocity of the microtubule. We demonstrate that even a single-microtubule trajectory suffices to obtain a reliable value of the persistence length. We do this by calculating the variance in the tangent trajectory angle of an individual microtubule. By averaging over many individual microtubule trajectories, we find that the persistence length of microtubule tips is 0.24 +/- 0.03 mm.

Auditory abilities of speakers who persisted, or recovered, from stuttering

PubMed Central

Howell, Peter; Davis, Stephen; Williams, Sheila M.

2006-01-01

Objective The purpose of this study was to see whether participants who persist in their stutter have poorer sensitivity in a backward masking task compared to those participants who recover from their stutter. Design The auditory sensitivity of 30 children who stutter was tested on absolute threshold, simultaneous masking, backward masking with a broadband and with a notched noise masker. The participants had been seen and diagnosed as stuttering at least 1 year before their 12th birthday. The participants were assessed again at age 12 plus to establish whether their stutter had persisted or recovered. Persistence or recovery was based on participant's, parent's and researcher's assessment and Riley's [Riley, G. D. (1994). Stuttering severity instrument for children and adults (3rd ed.). Austin, TX: Pro-Ed.] Stuttering Severity Instrument-3. Based on this assessment, 12 speakers had persisted and 18 had recovered from stuttering. Results Thresholds differed significantly between persistent and recovered groups for the broadband backward-masked stimulus (thresholds being higher for the persistent group). Conclusions Backward masking performance at teenage is one factor that distinguishes speakers who persist in their stutter from those who recover.

 Education objectives: Readers of this article should: (1) explain why auditory factors have been implicated in stuttering; (2) summarise the work that has examined whether peripheral, and/or central, hearing are problems in stuttering; (3) explain how the hearing ability of persistent and recovered stutterers may differ; (4) discuss how hearing disorders have been implicated in other language disorders. PMID:16920188

Predictors of Persistence in Online Graduate Nursing Students

ERIC Educational Resources Information Center

Cauble, Denise

2015-01-01

Persistence is an important measure of success for individual students and institutions of higher learning. The purpose of this study was to explore personal and academic factors that influence persistence in online graduate nursing students. A predictive correlational study design was used. Data were extracted from existing student records in two…

Initiation, Desistance, and Persistence of Men's Sexual Coercion

ERIC Educational Resources Information Center

Hall, Gordon C. Nagayama; Degarmo, David S.; Eap, Sopagna; Teten, Andra L.; Sue, Stanley

2006-01-01

Patterns of sexually coercive behavior were examined among 266 Asian American and 299 European American men over 1 year. Noncoercer (n = 358), desister (n = 120), initiator (n = 39), and persistent (n = 48) sexually coercive groups were identified. The strongest predictor of sexual coercion was past sexual coercion. Persistent sexual coercers were…

Long-term Persistence of Zoster Vaccine Efficacy

PubMed Central

Morrison, Vicki A.; Johnson, Gary R.; Schmader, Kenneth E.; Levin, Myron J.; Zhang, Jane H.; Looney, David J.; Betts, Robert; Gelb, Larry; Guatelli, John C.; Harbecke, Ruth; Pachucki, Connie; Keay, Susan; Menzies, Barbara; Griffin, Marie R.; Kauffman, Carol A.; Marques, Adriana; Toney, John; Boardman, Kathy; Su, Shu-Chih; Li, Xiaoming; Chan, Ivan S. F.; Parrino, Janie; Annunziato, Paula; Oxman, Michael N.; Davis, LE.; Kauffman, CA; Keay, SK; Straus, SE; Marques, AR; Soto, NE; Brunell, P; Gnann, JW; Serrao, R; Cotton, DJ; Goodman, RP; Arbeit, RD; Pachucki, CT; Levin, MJ; Schmader, KE; Keitel, WA; Greenberg, RN; Morrison, VA; Wright, PF; Griffin, MR; Simberkoff, MS; Yeh, SS; Lobo, Z; Holodniy, M; Loutit, J; Betts, RF; Gelb, LD; Crawford, GE; Guatelli, J; Brooks, PA; Looney, DJ; Neuzil, KM; Toney, JF; Kauffman, CA; Keay, SK; Marques, AR; Pachucki, CT; Levin, MJ; Schmader, KE; Morrison, VA; Wright, PF; Griffin, MR; Betts, RF; Gelb, LD; Guatelli, JC; Looney, DJ; Neuzil, KM; Menzies, B; Toney, JF

2015-01-01

Background. The Shingles Prevention Study (SPS) demonstrated zoster vaccine efficacy through 4 years postvaccination. A Short-Term Persistence Substudy (STPS) demonstrated persistence of vaccine efficacy for at least 5 years. A Long-Term Persistence Substudy (LTPS) was undertaken to further assess vaccine efficacy in SPS vaccine recipients followed for up to 11 years postvaccination. Study outcomes were assessed for the entire LTPS period and for each year from 7 to 11 years postvaccination. Methods. Surveillance, case determination, and follow-up were comparable to those in SPS and STPS. Because SPS placebo recipients were offered zoster vaccine before the LTPS began, there were no unvaccinated controls. Instead, SPS and STPS placebo results were used to model reference placebo groups. Results. The LTPS enrolled 6867 SPS vaccine recipients. Compared to SPS, estimated vaccine efficacy in LTPS decreased from 61.1% to 37.3% for the herpes zoster (HZ) burden of illness (BOI), from 66.5% to 35.4% for incidence of postherpetic neuralgia, and from 51.3% to 21.1% for incidence of HZ, and declined for all 3 outcome measures from 7 through 11 years postvaccination. Vaccine efficacy for the HZ BOI was significantly greater than zero through year 10 postvaccination, whereas vaccine efficacy for incidence of HZ was significantly greater than zero only through year 8. Conclusions. Estimates of vaccine efficacy decreased over time in the LTPS population compared with modeled control estimates. Statistically significant vaccine efficacy for HZ BOI persisted into year 10 postvaccination, whereas statistically significant vaccine efficacy for incidence of HZ persisted only through year 8. PMID:25416754

Persistence in eye movement during visual search

NASA Astrophysics Data System (ADS)

Amor, Tatiana A.; Reis, Saulo D. S.; Campos, Daniel; Herrmann, Hans J.; Andrade, José S.

2016-02-01

As any cognitive task, visual search involves a number of underlying processes that cannot be directly observed and measured. In this way, the movement of the eyes certainly represents the most explicit and closest connection we can get to the inner mechanisms governing this cognitive activity. Here we show that the process of eye movement during visual search, consisting of sequences of fixations intercalated by saccades, exhibits distinctive persistent behaviors. Initially, by focusing on saccadic directions and intersaccadic angles, we disclose that the probability distributions of these measures show a clear preference of participants towards a reading-like mechanism (geometrical persistence), whose features and potential advantages for searching/foraging are discussed. We then perform a Multifractal Detrended Fluctuation Analysis (MF-DFA) over the time series of jump magnitudes in the eye trajectory and find that it exhibits a typical multifractal behavior arising from the sequential combination of saccades and fixations. By inspecting the time series composed of only fixational movements, our results reveal instead a monofractal behavior with a Hurst exponent , which indicates the presence of long-range power-law positive correlations (statistical persistence). We expect that our methodological approach can be adopted as a way to understand persistence and strategy-planning during visual search.

High School Economic Composition and College Persistence.

PubMed

Niu, Sunny X; Tienda, Marta

2013-02-01

Using a longitudinal sample of Texas high school seniors of 2002 who enrolled in college within the calendar year of high school graduation, we examine variation in college persistence according to the economic composition of their high schools, which serves as a proxy for unmeasured high school attributes that are conductive to postsecondary success. Students who graduated from affluent high schools have the highest persistence rates and those who attended poor high schools have the lowest rates. Multivariate analyses indicate that the advantages in persistence and on-time graduation from four-year colleges enjoyed by graduates of affluent high schools cannot be fully explained by high school college orientation and academic rigor, family background, pre-college academic preparedness or the institutional characteristics. High school college orientation, family background and pre-college academic preparation largely explain why graduates from affluent high schools who first enroll in two-year colleges have higher transfer rates to four-year institutions; however these factors and college characteristics do not explain the lower transfer rates for students from poor high schools. The conclusion discusses the implications of the empirical findings in light of several recent studies that call attention to the policy importance of high schools as a lever to improve persistence and completion rates via better institutional matches.

Spreading of persistent infections in heterogeneous populations

NASA Astrophysics Data System (ADS)

Sanz, J.; Floría, L. M.; Moreno, Y.

2010-05-01

Up to now, the effects of having heterogeneous networks of contacts have been studied mostly for diseases which are not persistent in time, i.e., for diseases where the infectious period can be considered very small compared to the lifetime of an individual. Moreover, all these previous results have been obtained for closed populations, where the number of individuals does not change during the whole duration of the epidemics. Here, we go one step further and analyze, both analytically and numerically, a radically different kind of diseases: those that are persistent and can last for an individual’s lifetime. To be more specific, we particularize to the case of tuberculosis’ (TB) infection dynamics, where the infection remains latent for a period of time before showing up and spreading to other individuals. We introduce an epidemiological model for TB-like persistent infections taking into account the heterogeneity inherent to the population structure. This sort of dynamics introduces new analytical and numerical challenges that we are able to sort out. Our results show that also for persistent diseases the epidemic threshold depends on the ratio of the first two moments of the degree distribution so that it goes to zero in a class of scale-free networks when the system approaches the thermodynamic limit.

High School Economic Composition and College Persistence

PubMed Central

Tienda, Marta

2013-01-01

Using a longitudinal sample of Texas high school seniors of 2002 who enrolled in college within the calendar year of high school graduation, we examine variation in college persistence according to the economic composition of their high schools, which serves as a proxy for unmeasured high school attributes that are conductive to postsecondary success. Students who graduated from affluent high schools have the highest persistence rates and those who attended poor high schools have the lowest rates. Multivariate analyses indicate that the advantages in persistence and on-time graduation from four-year colleges enjoyed by graduates of affluent high schools cannot be fully explained by high school college orientation and academic rigor, family background, pre-college academic preparedness or the institutional characteristics. High school college orientation, family background and pre-college academic preparation largely explain why graduates from affluent high schools who first enroll in two-year colleges have higher transfer rates to four-year institutions; however these factors and college characteristics do not explain the lower transfer rates for students from poor high schools. The conclusion discusses the implications of the empirical findings in light of several recent studies that call attention to the policy importance of high schools as a lever to improve persistence and completion rates via better institutional matches. PMID:23459198

Emerging Voices: Resituating Expertise--An Activity Theory Perspective on Representation in Critical Ethnography

ERIC Educational Resources Information Center

Stinnett, Jerry

2012-01-01

Ethnography has consistently faced ethical questions since the earliest postmodern critiques of the ethnographer's claims to objectivity in descriptive research. Concerns of how to represent ethically the ethnographic Other, to engage in activist research, and to foster collaboration among researchers and participants persist even in the age of…

High turnover drives prolonged persistence of influenza in managed pig herds

PubMed Central

Aguas, Ricardo; Riley, Steven; Loeffen, Willie L. A.; Wood, James L. N.; Grenfell, Bryan T.

2016-01-01

Pigs have long been hypothesized to play a central role in the emergence of novel human influenza A virus (IAV) strains, by serving as mixing vessels for mammalian and avian variants. However, the key issue of viral persistence in swine populations at different scales is ill understood. We address this gap using epidemiological models calibrated against seroprevalence data from Dutch finishing pigs to estimate the ‘critical herd size’ (CHS) for IAV persistence. We then examine the viral phylogenetic evidence for persistence by comparing human and swine IAV. Models suggest a CHS of approximately 3000 pigs above which influenza was likely to persist, i.e. orders of magnitude lower than persistence thresholds for IAV and other acute viruses in humans. At national and regional scales, we found much stronger empirical signatures of prolonged persistence of IAV in swine compared with human populations. These striking levels of persistence in small populations are driven by the high recruitment rate of susceptible piglets, and have significant implications for management of swine and for overall patterns of genetic diversity of IAV. PMID:27358277

Persistent Poverty in Rural America. Rural Studies Series.

ERIC Educational Resources Information Center

Rural Sociological Society, Bozeman, MT.

In this volume, the Rural Sociological Society Task Force on Persistent Rural Poverty analyzes the leading explanations of persistent rural poverty and points out new directions in theory that should provide a firmer foundation for antipoverty policies and programs. Written by over 50 leading social scientists, the Task Force report explains that…

Directional analysis of CO2 persistence at a rural site.

PubMed

Pérez, Isidro A; Sánchez, M Luisa; García, M Ángeles; Paredes, Vanessa

2011-09-01

Conditional probability was used to establish persistence of CO(2) concentrations at a rural site. Measurements extended over three years and were performed with a CO(2) continuous monitor and a sodar. Concentrations in the usual range at this site were proposed as the truncation level to calculate conditional probability, allowing us to determine the extent of CO(2) sequences. Extension of episodes may be inferred from these values. Persistence of wind directions revealed two groups of sectors, one with a persistence of about 16 h and another of about 9 h. Cumulative distribution of CO(2) was calculated in each wind sector and three groups, associated with different concentration origins, were established. One group was linked to transport and local sources, another to the rural environment, and a third to transport of clean air masses. Daily evolution of concentrations revealed major differences during the night and monthly analysis allowed us to associate group 1 with the vegetation cycle and group 3 with wind speed from December to April. Persistence of concentrations was obtained, and group 3 values were lower for concentrations above the truncation level, whereas persistence of groups 1 and 2 was similar. However, group 3 persistence was, in general, between group 1 and 2 persistence for concentrations below the truncation level. Copyright © 2011 Elsevier B.V. All rights reserved.

Bowman’s layer encystment in cases of persistent Acanthamoeba keratitis

PubMed Central

Yokogawa, Hideaki; Kobayashi, Akira; Yamazaki, Natsuko; Ishibashi, Yasuhisa; Oikawa, Yosaburo; Tokoro, Masaharu; Sugiyama, Kazuhisa

2012-01-01

Background The purpose of this study was to report Acanthamoeba encystment in Bowman’s layer in Japanese cases of persistent Acanthamoeba keratitis (AK). Methods Laser confocal microscopic images of the cornea were obtained in vivo from 18 consecutive eyes from 17 confirmed AK patients. Retrospectively, 14 cases treated over 4 months were categorized as a nonpersistent group and three cases that required prolonged therapy for more than 6 months were categorized as a persistent group. Clinical outcomes based on final best-corrected visual acuity were retrospectively analyzed, and selected confocal images were evaluated qualitatively for abnormal findings. Results The final best-corrected visual acuity was significantly lower (P < 0.01) for patients in the persistent group compared with that in the nonpersistent group. At the initial visit, in vivo confocal microscopy demonstrated Acanthamoeba cysts exclusively in the epithelial layer in both the nonpersistent group (80%) and the persistent group (100%). At a subsequent follow-up visit, numerous Acanthamoeba cysts were observed in the epithelial cell layer and in Bowman’s layer in all patients with persistent AK, but Acanthamoeba cysts were undetectable in all cases with nonpersistent AK tested. Conclusion Invasion of cysts into Bowman’s layer was characteristically observed in patients with persistence of AK. This finding suggests that invasion of Acanthamoeba cysts into Bowman’s layer may be a useful predictor for a persistent clinical course. PMID:22927735

Toward Rechargeable Persistent Luminescence for the First and Third Biological Windows via Persistent Energy Transfer and Electron Trap Redistribution.

PubMed

Xu, Jian; Murata, Daisuke; Ueda, Jumpei; Viana, Bruno; Tanabe, Setsuhisa

2018-05-07

Persistent luminescence (PersL) imaging without real-time external excitation has been regarded as the next generation of autofluorescence-free optical imaging technology. However, to achieve improved imaging resolution and deep tissue penetration, developing new near-infrared (NIR) persistent phosphors with intense and long duration PersL over 1000 nm is still a challenging but urgent task in this field. Herein, making use of the persistent energy transfer process from Cr 3+ to Er 3+ , we report a novel garnet persistent phosphor of Y 3 Al 2 Ga 3 O 12 codoped with Er 3+ and Cr 3+ (YAG G:Er-Cr), which shows intense Cr 3+ PersL (∼690 nm) in the deep red region matching well with the first biological window (NIR-I, 650-950 nm) and Er 3+ PersL (∼1532 nm) in the NIR region matching well with the third biological window (NIR-III, 1500-1800 nm). The optical imaging through raw-pork tissues (thickness of 1 cm) suggests that the emission band of Er 3+ can achieve higher spatial resolution and more accurate signal location than that of Cr 3+ due to the reduced light scattering at longer wavelengths. Furthermore, by utilizing two independent electron traps with two different trap depths in YAG G:Er-Cr, the Cr 3+ /Er 3+ PersL can even be recharged in situ by photostimulation with 660 nm LED thanks to the redistribution of trapped electrons from the deep trap to the shallow one. Our results serve as a guide in developing promising NIR (>1000 nm) persistent phosphors for long-term optical imaging.

Persistency of milk yield in Indonesian Holstein cows

NASA Astrophysics Data System (ADS)

Widyas, N.; Putra, F. Y.; Nugroho, T.; Pramono, A.; Susilowati, A.; Sutarno; Prastowo, S.

2018-03-01

Milk yield is an important trait in dairy industry; thus, information regarding this phenotype is essential to measure the productivity of a farm. Total milk yield in one lactation period was often predicted using information from samples collected within certain time intervals. The rate of change of milk production between two-time intervals is defined as persistency. This article aims to estimate the persistency of milk yield between lactation 1, 2 and 3 in Indonesian Friesian Holstein (IFH) cows. Data was collected from Limpakuwus stable, Baturraden Dairy Cattle Breeding Centre, Central Java Indonesia. Records were obtained from cows which started lactating on 2013 until the end of third lactation around the beginning of 2016. Milk yield from the first (L1), second (L2) and third (L3) lactations of 21 cows were recorded in kilograms. Samples were collected in 30 days basis interval started from the 10th day of lactation up to the 10th month. In this population, the cows first calving was around February – April 2013; while the second and third calving occurred all over the relevant year. The mean of milk yield for L1, L2 and L3 were 17.77±3.70, 16.09±5.17 and 13.73±4.02 Kg respectively. The peak of milk yields was achieved at the second month of the lactation for L1, L2 and L3. The persistency from the second to the tenth test days were 97, 93 and 94% for L1, L2 and L3, respectively. Milk yield persistency is representing ability of cow in maintain milk production after peak during lactation period. The more persistent shows better performance of dairy cattle as well as farm management. For that, persistency value could be used as valuable information in evaluating the management in Indonesian dairy farms.

Personality and Persistence in Education: A Longitudinal Study.

ERIC Educational Resources Information Center

Gottfredson, Denise C.

Persistence in educational pursuits is strongly related to the prestige level and income level of an occupation. Personality correlates of persistence in education were examined in the context of a causal model of attainment in an eight-year longitudinal study of a nationally representative sample of 2213 young men. Results imply that anxiety and…

A Longitudinal Behavioral Genetic Analysis of Task Persistence

ERIC Educational Resources Information Center

Deater-Deckard, Kirby; Petrill, Stephen A.; Thompson, Lee A.; DeThorne, Laura S.

2006-01-01

Change in task persistence was assessed in two annual assessments using teachers', testers', and observers' ratings. Participants included 79 monozygotic and 116 same-sex dizygotic twin pairs who were in Kindergarten or 1st grade (4.3 to 7.9 years old) at the initial assessment. Task persistence was widely distributed and higher among older…

New daily persistent headache in children and adults.

PubMed

Mack, Kenneth J

2009-02-01

New daily persistent headache (NDPH) is frequently seen in young patients with chronic daily headache. NDPH begins with a sudden onset, often associated with an infection or other physical stress. This headache syndrome is difficult to treat and may persist for years. This review discusses the epidemiology, comorbid symptoms, evaluation, and treatment of this disorder.

PAQ: Persistent Adaptive Query Middleware for Dynamic Environments

NASA Astrophysics Data System (ADS)

Rajamani, Vasanth; Julien, Christine; Payton, Jamie; Roman, Gruia-Catalin

Pervasive computing applications often entail continuous monitoring tasks, issuing persistent queries that return continuously updated views of the operational environment. We present PAQ, a middleware that supports applications' needs by approximating a persistent query as a sequence of one-time queries. PAQ introduces an integration strategy abstraction that allows composition of one-time query responses into streams representing sophisticated spatio-temporal phenomena of interest. A distinguishing feature of our middleware is the realization that the suitability of a persistent query's result is a function of the application's tolerance for accuracy weighed against the associated overhead costs. In PAQ, programmers can specify an inquiry strategy that dictates how information is gathered. Since network dynamics impact the suitability of a particular inquiry strategy, PAQ associates an introspection strategy with a persistent query, that evaluates the quality of the query's results. The result of introspection can trigger application-defined adaptation strategies that alter the nature of the query. PAQ's simple API makes developing adaptive querying systems easily realizable. We present the key abstractions, describe their implementations, and demonstrate the middleware's usefulness through application examples and evaluation.

Immune Evasion Strategies and Persistence of Helicobacter pylori.

PubMed

Mejías-Luque, Raquel; Gerhard, Markus

Helicobacter pylori infection is commonly acquired during childhood, can persist lifelong if not treated, and can cause different gastric pathologies, including chronic gastritis, peptic ulcer disease, and eventually gastric cancer. H. pylori has developed a number of strategies in order to cope with the hostile conditions found in the human stomach as well as successful mechanisms to evade the strong innate and adaptive immune responses elicited upon infection. Thus, by manipulating innate immune receptors and related signaling pathways, inducing tolerogenic dendritic cells and inhibiting effector T cell responses, H. pylori ensures low recognition by the host immune system as well as its persistence in the gastric epithelium. Bacterial virulence factors such as cytotoxin-associated gene A, vacuolating cytotoxin A, or gamma-glutamyltranspeptidase have been extensively studied in the context of bacterial immune escape and persistence. Further, the bacterium possesses other factors that contribute to immune evasion. In this chapter, we discuss in detail the main evasion and persistence strategies evolved by the bacterium as well as the specific bacterial virulence factors involved.

Persister formation in Staphylococcus aureus is associated with ATP depletion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conlon, Brian P.; Rowe, Sarah E.; Gandt, Autumn Brown

Persisters are dormant phenotypic variants of bacterial cells that are tolerant to killing by antibiotics1. Persisters are associated with chronic bacterial infection and antibiotic treatment failure. In Escherichia coli, toxin/antitoxin (TA) modules are responsible for persister formation. The mechanism of persister formation in Gram positive bacteria is unknown. Staphylococcus aureus is a major human pathogen, responsible for a variety of chronic and relapsing infections such as osteomyelitis, endocarditis and infections of implanted devices. Deleting TA modules in S. aureus did not affect the level of persisters. Here we show that S. aureus persisters are produced due to a stochastic entrancemore » to stationary phase accompanied by a drop in intracellular ATP. Cells expressing stationary state markers are present throughout the growth phase, increasing in frequency with cell density. Cell sorting revealed that expression of stationary markers was associated with a 100-1000 fold increased likelihood of survival to antibiotic challenge. We find that the antibiotic tolerance of these cells is due to a drop in intracellular ATP. The ATP level of the cell is predictive of bactericidal antibiotic efficacy and explains bacterial tolerance to antibiotic treatment.« less

Persistent increased PKMζ in long-term and remote spatial memory.

PubMed

Hsieh, Changchi; Tsokas, Panayiotis; Serrano, Peter; Hernández, A Iván; Tian, Dezhi; Cottrell, James E; Shouval, Harel Z; Fenton, André Antonio; Sacktor, Todd Charlton

2017-02-01

PKMζ is an autonomously active PKC isoform that is thought to maintain both LTP and long-term memory. Whereas persistent increases in PKMζ protein sustain the kinase's action in LTP, the molecular mechanism for the persistent action of PKMζ during long-term memory has not been characterized. PKMζ inhibitors disrupt spatial memory when introduced into the dorsal hippocampus from 1day to 1month after training. Therefore, if the mechanisms of PKMζ's persistent action in LTP maintenance and long-term memory were similar, persistent increases in PKMζ would last for the duration of the memory, far longer than most other learning-induced gene products. Here we find that spatial conditioning by aversive active place avoidance or appetitive radial arm maze induces PKMζ increases in dorsal hippocampus that persist from 1day to 1month, coinciding with the strength and duration of memory retention. Suppressing the increase by intrahippocampal injections of PKMζ-antisense oligodeoxynucleotides prevents the formation of long-term memory. Thus, similar to LTP maintenance, the persistent increase in the amount of autonomously active PKMζ sustains the kinase's action during long-term and remote spatial memory maintenance. Copyright © 2016. Published by Elsevier Inc.

Persistent Identifiers for Data Products: Adoption, Enhancement, and Use

NASA Astrophysics Data System (ADS)

Downs, R. R.; Schumacher, J.; Scialdone, J.; Hansen, M.

2016-12-01

Persistent identifiers offer value for science and for various science community stakeholders, such as data producers, data distributers, science article authors, scientific journal publishers, research sponsors, libraries, and affiliated institutions. However, to attain the benefits of persistent identifiers, they should be assigned to disseminated data products and included within the references reported in publications that describe the studies in which the data were used. Scientific data centers, archives, digital repositories, and other data publishers also need to determine the level of aggregation, or granularity, of data products to be assigned persistent identifiers as well as the elements to be included in the landing pages to which persistent identifiers will resolve. Similarly, policies and procedures should be clear on decisions about maintenance issues, including versioning of data products and how persistent identifiers to previous versions and new locations will be maintained. With some persistent identifiers, such as Digital Object Identifiers (DOIs), which provide capabilities to link to related identifiers of other works, decisions on the establishment of links also must be clear, including links between early versions of data products and subsequent versions, links between data products and associated documentation, and links between data products and other publications that describe the data. We describe decisions for enabling the adoption and assignment of DOIs as persistent identifiers for data products disseminated by the NASA Socioeconomic Data and Applications Center (SEDAC) along with considerations for policy decisions, testing, implementation, and enhancement. The prevalence of the adoption of DOIs for citing the use of Earth science data disseminated by SEDAC also is described to provide insight into how interdisciplinary data users have engaged in the use of DOIs within their publications along with the implications of such use.

Clinical and prognostic subforms of new daily-persistent headache.

PubMed

Robbins, M S; Grosberg, B M; Napchan, U; Crystal, S C; Lipton, R B

2010-04-27

According to the International Classification of Headache Disorders (ICHD)-2, primary daily headaches unremitting from onset are classified as new daily-persistent headache (NDPH) only if migraine features are absent. When migraine features are present, classification is problematic. We developed a revised NDPH definition not excluding migraine features (NDPH-R), and applied it to consecutive patients seen at the Montefiore Headache Center. We divided this group into patients meeting ICHD-2 criteria (NDPH-ICHD) and those with too many migraine features for ICHD-2 (NDPH-mf). We compared clinical and demographic features in these groups, identifying 3 prognostic subgroups: persisting, remitting, and relapsing-remitting. Remitting and relapsing-remitting patients were combined into a nonpersisting group. Of 71 NDPH-R patients, 31 (43.7%) also met NDPH-ICHD-2 criteria. The NDPH-mf and the NDPH-ICHD-2 groups were similar in most clinical features though the NDPH-mf group was younger, included more women, and had a higher frequency of depression. The groups were similar in the prevalence of allodynia, triptan responsiveness, and prognosis. NDPH-R prognostic subforms were also very similar, although the persisting subform was more likely to be of white race, to have anxiety or depression, and to have a younger onset age. Current International Classification of Headache Disorders (ICHD)-2 criteria exclude the majority of patients with primary headache unremitting from onset. The proposed criteria for revised new daily-persistent headache definition not excluding migraine features (NDPH-R) classify these patients into a relatively homogeneous group based on demographics, clinical features, and prognosis. Both new daily-persistent headache with too many migraine features for ICHD-2 and new daily-persistent headache meeting ICHD-2 criteria include patients in equal proportions that fall into the persisting, remitting, and relapsing-remitting subgroups. Our criteria for NDPH

Persistent fluctuations in stride intervals under fractal auditory stimulation.

PubMed

Marmelat, Vivien; Torre, Kjerstin; Beek, Peter J; Daffertshofer, Andreas

2014-01-01

Stride sequences of healthy gait are characterized by persistent long-range correlations, which become anti-persistent in the presence of an isochronous metronome. The latter phenomenon is of particular interest because auditory cueing is generally considered to reduce stride variability and may hence be beneficial for stabilizing gait. Complex systems tend to match their correlation structure when synchronizing. In gait training, can one capitalize on this tendency by using a fractal metronome rather than an isochronous one? We examined whether auditory cues with fractal variations in inter-beat intervals yield similar fractal inter-stride interval variability as isochronous auditory cueing in two complementary experiments. In Experiment 1, participants walked on a treadmill while being paced by either an isochronous or a fractal metronome with different variation strengths between beats in order to test whether participants managed to synchronize with a fractal metronome and to determine the necessary amount of variability for participants to switch from anti-persistent to persistent inter-stride intervals. Participants did synchronize with the metronome despite its fractal randomness. The corresponding coefficient of variation of inter-beat intervals was fixed in Experiment 2, in which participants walked on a treadmill while being paced by non-isochronous metronomes with different scaling exponents. As expected, inter-stride intervals showed persistent correlations similar to self-paced walking only when cueing contained persistent correlations. Our results open up a new window to optimize rhythmic auditory cueing for gait stabilization by integrating fractal fluctuations in the inter-beat intervals.

Tracing Life in the Earliest Terrestrial Rock Record

NASA Astrophysics Data System (ADS)

Lepland, A.; van Zuilen, M.; Arrhenius, G.

2001-12-01

The principal method for studying the earliest traces of life in the metamorphosed, oldest (> 3.5 Ga) terrestrial rocks involves determination of isotopic composition of carbon, mainly prevailing as graphite. It is generally believed that this measure can distinguish biogenic graphite from abiogenic varieties. However, the interpretation of life from carbon isotope ratios has to be assessed within the context of specific geologic circumstances requiring (i) reliable protolith interpretation (ii) control of secondary, metasomatic processes, and (iii) understanding of different graphite producing mechanisms and related carbon isotopic systematics. We have carried out a systematic study of abundance, isotopic composition and petrographic associations of graphite in rocks from the ca. 3.8 Ga Isua Supracrustal Belt (ISB) in southern West Greenland. Our study indicates that most of the graphite in ISB occurs in carbonate-rich metasomatic rocks (metacarbonates) while sedimentary units, including banded iron formations (BIFs) and metacherts, have exceedingly low graphite concentrations. Regardless of isotopic composition of graphite in metacarbonate rocks, their secondary origin disqualifies them from providing evidence for traces of life stemming from 3.8 Ga. Recognition of the secondary origin of Isua metacarbonates thus calls for reevaluation of biologic interpretations by Schidlowski et al. (1979) and Mojzsis et al. (1996) that suggested the occurrence of 3.8 Ga biogenic graphite in these rocks. The origin of minute quantities of reduced carbon, released from sedimentary BIFs and metacherts at combustion steps > 700 C remains to be clarified. Its isotopic composition (d13C from -18 to -25%) may hint at a biogenic origin. However, such isotopically light carbon was also found in Proterozoic mafic dykes cross-cutting the metasedimentary units in the ISB. The occurrence of isotopically light, reduced carbon in biologically irrelevant dykes may indicate secondary graphite

Ratio-based estimators for a change point in persistence.

PubMed

Halunga, Andreea G; Osborn, Denise R

2012-11-01

We study estimation of the date of change in persistence, from [Formula: see text] to [Formula: see text] or vice versa. Contrary to statements in the original papers, our analytical results establish that the ratio-based break point estimators of Kim [Kim, J.Y., 2000. Detection of change in persistence of a linear time series. Journal of Econometrics 95, 97-116], Kim et al. [Kim, J.Y., Belaire-Franch, J., Badillo Amador, R., 2002. Corringendum to "Detection of change in persistence of a linear time series". Journal of Econometrics 109, 389-392] and Busetti and Taylor [Busetti, F., Taylor, A.M.R., 2004. Tests of stationarity against a change in persistence. Journal of Econometrics 123, 33-66] are inconsistent when a mean (or other deterministic component) is estimated for the process. In such cases, the estimators converge to random variables with upper bound given by the true break date when persistence changes from [Formula: see text] to [Formula: see text]. A Monte Carlo study confirms the large sample downward bias and also finds substantial biases in moderate sized samples, partly due to properties at the end points of the search interval.

Evaluating multimedia chemical persistence: Classification and regression tree analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, D.H.; McKone, T.E.; Kastenberg, W.E.

2000-04-01

For the thousands of chemicals continuously released into the environment, it is desirable to make prospective assessments of those likely to be persistent. Widely distributed persistent chemicals are impossible to remove from the environment and remediation by natural processes may take decades, which is problematic if adverse health or ecological effects are discovered after prolonged release into the environment. A tiered approach using a classification scheme and a multimedia model for determining persistence is presented. Using specific criteria for persistence, a classification tree is developed to classify a chemical as persistent or nonpersistent based on the chemical properties. In thismore » approach, the classification is derived from the results of a standardized unit world multimedia model. Thus, the classifications are more robust for multimedia pollutants than classifications using a single medium half-life. The method can be readily implemented and provides insight without requiring extensive and often unavailable data. This method can be used to classify chemicals when only a few properties are known and can be used to direct further data collection. Case studies are presented to demonstrate the advantages of the approach.« less

Community-acquired methicillin-resistant Staphylococcus aureus can persist in the throat.

PubMed

Hamdan-Partida, Aida; González-García, Samuel; de la Rosa García, Estela; Bustos-Martínez, Jaime

2018-06-01

Colonization by Staphylococcus aureus is an important factor in infections caused by this microorganism. Among the colonization niches of staphylococci are the nose, skin, intestinal tract, and, recently, the throat has been given relevance. Infections caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) can be fatal. Persistence of S. aureus is an important process in the pathogenesis of this microorganism and must be studied. The aim of this study was to determine the persistence of S. aureus in the throat, and characterized the strains. We studied the persistence of S. aureus for 6 years in the throat of apparently healthy people. The isolated strains from the persistent carriers were characterized through PFGE, spa-typing, SCCmec typing, resistance to methicillin, presence of virulence genes (adhesins and toxins), and the formation of biofilm. We found persistent and intermittent carriers of S. aureus in the throat, with methicillin-sensitive (MSSA), methicillin-resistant (MRSA) strains, and confirmed for the first time that CA-MRSA colonizes this niche. These strains can colonize persistently the throat for four years or more. Typification of strains through PFGE and spa-typing revealed that some carriers present the same strain, whereas others present different strains along the period of persistence. Almost all strains induced a strong biofilm formation. All strains presented adhesin and toxin genes, but no shared genotype was found. We conclude that S. aureus, including CA-MRSA strains, can remain persistently in the throat, finding a wide variability among the persistent strains. Copyright © 2018 Elsevier GmbH. All rights reserved.

Transient, but not persistent, adult food insecurity influences toddler development.

PubMed

Hernandez, Daphne C; Jacknowitz, Alison

2009-08-01

In this study, we examined characteristics associated with experiencing persistent and transitional adult food insecurity and how persistent and transitional adult food insecurity influences toddler cognitive and motor development, along with toddler's weight and health status. Using the first 2 waves of the Early Childhood Longitudinal Study-Birth Cohort, 4 mutually exclusive variables capturing persistent and transitional adult food insecurity were created to capture those adults that experience adult food insecurity in the following: both waves, in 1 wave (at 9 or 24 mo after birth), and never experience food insecurity. We used logistic regression models to estimate characteristics associated with the likelihood of experiencing persistent and transitional adult food insecurity. Ordinary least squares regression models were used to estimate how persistent and transitional adult food insecurity influences toddler development. Similar factors influenced one's likelihood of experiencing adult transitional and persistent food insecurity; individuals who experienced any food insecurity were more economically disadvantaged. Thus, outreach efforts do not need to vary by duration of food insecurity. Whereas negative effects of food insecurity on school-aged children are found in the literature, it appears toddlers are buffered from the effects of persistent adult food insecurity. Our findings suggest that toddlers residing with a temporarily food-insecure adult compared with a never food-insecure adult experienced immediate, but small, negative effects on their development. Hence, outreach and assistance may lessen immediate impacts of food insecurity on toddler development.

Information persistence using XML database technology

NASA Astrophysics Data System (ADS)

Clark, Thomas A.; Lipa, Brian E. G.; Macera, Anthony R.; Staskevich, Gennady R.

2005-05-01

The Joint Battlespace Infosphere (JBI) Information Management (IM) services provide information exchange and persistence capabilities that support tailored, dynamic, and timely access to required information, enabling near real-time planning, control, and execution for DoD decision making. JBI IM services will be built on a substrate of network centric core enterprise services and when transitioned, will establish an interoperable information space that aggregates, integrates, fuses, and intelligently disseminates relevant information to support effective warfighter business processes. This virtual information space provides individual users with information tailored to their specific functional responsibilities and provides a highly tailored repository of, or access to, information that is designed to support a specific Community of Interest (COI), geographic area or mission. Critical to effective operation of JBI IM services is the implementation of repositories, where data, represented as information, is represented and persisted for quick and easy retrieval. This paper will address information representation, persistence and retrieval using existing database technologies to manage structured data in Extensible Markup Language (XML) format as well as unstructured data in an IM services-oriented environment. Three basic categories of database technologies will be compared and contrasted: Relational, XML-Enabled, and Native XML. These technologies have diverse properties such as maturity, performance, query language specifications, indexing, and retrieval methods. We will describe our application of these evolving technologies within the context of a JBI Reference Implementation (RI) by providing some hopefully insightful anecdotes and lessons learned along the way. This paper will also outline future directions, promising technologies and emerging COTS products that can offer more powerful information management representations, better persistence mechanisms and

Persistence: A Key Factor in Human Performance at Work.

ERIC Educational Resources Information Center

Blair, Daniel V.; Price, Donna J.

1998-01-01

Reviews the construct of persistence as it relates to achievement motivation at work. Topics include foundational concepts of persistence; achievement motivation theory; a human motivation model; goal-setting theory; self-efficacy theory; expectancy theory; task assignments; confidence; and perceived value. (LRW)

Mechanisms of HIV persistence in HIV reservoirs.

PubMed

Mzingwane, Mayibongwe L; Tiemessen, Caroline T

2017-03-01

The establishment and maintenance of HIV reservoirs that lead to persistent viremia in patients on antiretroviral drugs remains the greatest challenge of the highly active antiretroviral therapy era. Cellular reservoirs include resting memory CD4+ T lymphocytes, implicated as the major HIV reservoir, having a half-life of approximately 44 months while this is less than 6 hours for HIV in plasma. In some individuals, persistent viremia consists of invariant HIV clones not detected in circulating resting CD4+ T lymphocytes suggesting other possible sources of residual viremia. Some anatomical reservoirs that may harbor such cells include the brain and the central nervous system, the gastrointestinal tract and the gut-associated lymphoid tissue and other lymphoid organs, and the genital tract. The presence of immune cells and other HIV susceptible cells, occurring in differing compositions in anatomical reservoirs, coupled with variable and poor drug penetration that results in suboptimal drug concentrations in some sites, are all likely factors that fuel the continued low-level replication and persistent viremia during treatment. Latently, HIV-infected CD4+ T cells harboring replication-competent virus, HIV cell-to-cell spread, and HIV-infected T cell homeostatic proliferation due to chronic immune activation represent further drivers of this persistent HIV viremia during highly active antiretroviral therapy. Copyright © 2017 John Wiley & Sons, Ltd.

Engineering success: Undergraduate Latina women's persistence in an undergradute engineering program

NASA Astrophysics Data System (ADS)

Rosbottom, Steven R.

The purpose and focus of this narrative inquiry case study were to explore the personal stories of four undergraduate Latina students who persist in their engineering programs. This study was guided by two overarching research questions: a) What are the lived experiences of undergraduate Latina engineering students? b) What are the contributing factors that influence undergraduate Latina students to persist in an undergraduate engineering program? Yosso's (2005) community cultural wealth was used to the analyze data. Findings suggest through Yosso's (2005) aspirational capital, familial capital, social capital, navigational capital, and resistant capital the Latina student persisted in their engineering programs. These contributing factors brought to light five themes that emerged, the discovery of academic passions, guidance and support of family and teachers, preparation for and commitment to persistence, the power of community and collective engagement, and commitment to helping others. The themes supported their persistence in their engineering programs. Thus, this study informs policies, practices, and programs that support undergraduate Latina engineering student's persistence in engineering programs.

Persisting nutritional neuropathy amongst former war prisoners.

PubMed Central

Gill, G V; Bell, D R

1982-01-01

Of 898 former Far East prisoners of war, assessed between 1968 and 1981, 49 (5.5%) had evidence of persisting symptomatic neurological disease dating back to their periods of malnutrition in captivity. The commonest syndromes were peripheral neuropathy (often of "burning foot" type), optic atrophy, and sensori-neural deafness. Though nutritional neuropathies disappeared soon after release in most ex-Far East prisoners of war, in some they have persisted up to 36 years since exposure to the nutritional insult. PMID:6292369

Zebrafish monosex population reveals female dominance in sex determination and earliest events of gonad differentiation.

PubMed

Tong, Sok-Keng; Hsu, Hwei-Jan; Chung, Bon-chu

2010-08-15

The zebrafish is a popular model for genetic analysis and its sex differentiation has been the focus of attention for breeding purposes. Despite numerous efforts, very little is known about the mechanism of zebrafish sex determination. The lack of discernible sex chromosomes and the difficulty of distinguishing the sex of juvenile fish are two major obstacles that hamper the progress in such studies. To alleviate these problems, we have developed a scheme involving methyltestosterone treatment followed by natural mating to generate fish with predictable sex trait. Female F1 fish that gave rise to all-female offspring were generated. This predictable sex trait enables characterization of gonadal development in juvenile fish by histological examination and gene expression analysis. We found the first sign of zebrafish sex differentiation to be ovarian gonocyte proliferation and differentiation at 10 to 12 days post-fertilization (dpf). Somatic genes were expressed indifferently at 10 to 17 dpf, and then became sexually dimorphic at three weeks. This result indicates clear distinction of male and female gonads derived independently from primordial gonads. We classified the earliest stages of zebrafish sex determination into the initial preparation followed by female germ cell growth, oocyte differentiation, and somatic differentiation. Our genetic selection scheme matches the prediction that female-dominant genetic factors are required to determine zebrafish sex. Copyright 2010 Elsevier Inc. All rights reserved.

Persistence of airline accidents.

PubMed

Barros, Carlos Pestana; Faria, Joao Ricardo; Gil-Alana, Luis Alberiko

2010-10-01

This paper expands on air travel accident research by examining the relationship between air travel accidents and airline traffic or volume in the period from 1927-2006. The theoretical model is based on a representative airline company that aims to maximise its profits, and it utilises a fractional integration approach in order to determine whether there is a persistent pattern over time with respect to air accidents and air traffic. Furthermore, the paper analyses how airline accidents are related to traffic using a fractional cointegration approach. It finds that airline accidents are persistent and that a (non-stationary) fractional cointegration relationship exists between total airline accidents and airline passengers, airline miles and airline revenues, with shocks that affect the long-run equilibrium disappearing in the very long term. Moreover, this relation is negative, which might be due to the fact that air travel is becoming safer and there is greater competition in the airline industry. Policy implications are derived for countering accident events, based on competition and regulation. © 2010 The Author(s). Journal compilation © Overseas Development Institute, 2010.

The Relationship between Self-Efficacy and Persistence in Adult Remedial Education

ERIC Educational Resources Information Center

Holmquist, Carol L.

2013-01-01

Despite the need, persistence in remediation hovers at 50% (NCES, 2002) while nearly one third of community college enrollees arrive under-prepared (Hess, 2009). Persistence is correlated with academic preparation (Nash & Kallenbach, 2009), and barriers to persistence include a number of demographic barriers (Education, 2006; Labaree, 2006).…

A Persistence Model for African American Male Urban Community College Students.

ERIC Educational Resources Information Center

Mason, Harold P.

1998-01-01

Studies Kennedy-King College's low level of persistence among African-American "nontraditional" male students, and the resulting high rate of departure before completing specified goals. Proposes a model of persistence to develop modes of action, program enhancements, and activities within the college to increase persistence level. (24…

Identification of Left Atrial Appendage Thrombi in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation Using Intra-Cardiac Echocardiography and Cardiac Computed Tomography.

PubMed

Ikegami, Yukinori; Tanimoto, Kojiro; Inagawa, Kohei; Shiraishi, Yasuyuki; Fuse, Jun; Sakamoto, Munehisa; Momiyama, Yukihiko; Takatsuki, Seiji

2017-12-25

Intracardiac echocardiography (ICE) and cardiac computed tomography (CCT), in addition to standard transesophageal echocardiography (TEE), have been used to identify left atrial (LA) thrombi prior to ablation for atrial fibrillation (AF). The clinical advantages of this, however, remain unclear. This study therefore investigated the advantages of additional pre-procedural LA appendage (LAA) thrombus evaluation using ICE and the clinical value of CCT in persistent and long-standing persistent AF.Methods and Results:We analyzed data from 108 consecutive patients with persistent and long-standing persistent AF who were scheduled to undergo AF ablation. TEE was performed within 24 h prior to ablation. ICE was performed for 97 patients in whom a thrombus was not detected on TEE. CCT was performed in 95 patients. Thrombus or sludge was detected on TEE in 11 patients (10.3%), for whom ablation was cancelled. Four additional patients were diagnosed with LAA thrombus on ICE. When TEE and ICE were used as the reference for thrombus detection, the sensitivity, specificity, positive predictive value, and negative predictive value of CCT for identifying contrast defects in the LAA were 100%, 81.0%, 40.7%, and 100%, respectively. ICE combined with TEE increased the detection rate of LAA thrombi in patients with persistent and long-standing persistent AF. Moreover, CCT had high sensitivity and negative predictive value for LAA thrombus detection.

Persistent toxic substances: sources, fates and effects.

PubMed

Wong, Ming H; Armour, Margaret-Ann; Naidu, Ravi; Man, Ming

2012-01-01

Persistent toxic substances (PTS) include the Stockholm persistent organic pollutants, like dichlorodiphenyltrichloroethane, polychlorinated biphenyls, dioxin/furan, etc., and organometallic compounds, like organomercury, organotin, and organolead, which all share the same characteristics of being persistent, toxic, bioaccumulative, and able to travel long distances through different media. The adverse health effects of some of the emerging chemicals like pentabromodiphenyl ether, bisphenol A, and di(2-ethylhexyl)phthalate, which are widely used in daily appliances (e.g., TVs, computers, mobile phones, plastic baby bottles), have become a public health concern due to more evidence now available showing their adverse effects like disturbance of the endocrine system and cancer. This article is an attempt to review the current status of PTS in our environment, citing case studies in China and North America, and whether our existing drinking water treatment and wastewater treatment processes are adequate in removing them from water. Some management issues of these emerging chemicals of concern are also discussed.

Improving Underrepresented Minority Student Persistence in STEM

PubMed Central

Estrada, Mica; Burnett, Myra; Campbell, Andrew G.; Campbell, Patricia B.; Denetclaw, Wilfred F.; Gutiérrez, Carlos G.; Hurtado, Sylvia; John, Gilbert H.; Matsui, John; McGee, Richard; Okpodu, Camellia Moses; Robinson, T. Joan; Summers, Michael F.; Werner-Washburne, Maggie; Zavala, MariaElena

2016-01-01

Members of the Joint Working Group on Improving Underrepresented Minorities (URMs) Persistence in Science, Technology, Engineering, and Mathematics (STEM)—convened by the National Institute of General Medical Sciences and the Howard Hughes Medical Institute—review current data and propose deliberation about why the academic “pathways” leak more for URM than white or Asian STEM students. They suggest expanding to include a stronger focus on the institutional barriers that need to be removed and the types of interventions that “lift” students’ interests, commitment, and ability to persist in STEM fields. Using Kurt Lewin’s planned approach to change, the committee describes five recommendations to increase URM persistence in STEM at the undergraduate level. These recommendations capitalize on known successes, recognize the need for accountability, and are framed to facilitate greater progress in the future. The impact of these recommendations rests upon enacting the first recommendation: to track successes and failures at the institutional level and collect data that help explain the existing trends. PMID:27543633

Persistent Identifiers for Dutch cultural heritage institutions

NASA Astrophysics Data System (ADS)

Ras, Marcel; Kruithof, Gijsbert

2016-04-01

Over the past years, more and more collections belonging to archives, libraries, media, museums, and knowledge institutes are being digitised and made available online. These are exciting times for ALM institutions. They are realising that, in the information society, their collections are goldmines. Unfortunately most heritage institutions in the Netherlands do not yet meet the basic preconditions for long-term availability of their collections. The digital objects often have no long lasting fixed reference yet. URL's and web addresses change. Some digital objects that were referenced in Europeana and other portals can no longer be found. References in scientific articles have a very short life span, which is damaging for scholarly research. In 2015, the Dutch Digital Heritage Network (NDE) has started a two-year work program to co-ordinate existing initiatives in order to improve the (long-term) accessibility of the Dutch digital heritage for a wide range of users, anytime, anyplace. The Digital Heritage Network is a partnership established on the initiative of the Ministry of Education, Culture and Science. The members of the NDE are large, national institutions that strive to professionally preserve and manage digital data, e.g. the National Library, The Netherlands Institute for Sound and Vision, the Netherlands Cultural Heritage Agency, the Royal Netherlands Academy of Arts and Sciences, the National Archive of the Netherlands and the DEN Foundation, and a growing number of associations and individuals both within and outside the heritage sector. By means of three work programmes the goals of the Network should be accomplished and improve the visibility, the usability and the sustainability of digital heritage. Each programme contains of a set of projects. Within the sustainability program a project on creating a model for persistent identifiers is taking place. The main goals of the project are (1) raise awareness among cultural heritage institutions on the

Stress-activated protein kinase activation is the earliest direct correlate to the induction of secretagogue-induced pancreatitis in rats.

PubMed

Grady, T; Dabrowski, A; Williams, J A; Logsdon, C D

1996-10-03

We compared the cellular events induced by hyperstimulation of rats with caerulein which induces acute pancreatitis, to bombesin, which does not induce pancreatitis. Both secretogogues induced the intracellular activation of trypsinogen and the colocalization of lysosomal hydrolases and zymogen granules within 10-15 minutes. These data indicate that these parameters, previously thought to be crucial initiating events of pancreatitis, are not definitive cellular markers of the disease. We then compared the abilities of the two secretagogues to activate stress-activated protein kinase (SAPK). Significant effects of caerulein hyperstimulation on SAPK activity were observed within 5 minutes, the maximum (57-fold) activation was evident after 15 minutes, and levels remained above control for at least 3 hours. In comparison, hyperstimulation with bombesin induced a maximal 5-fold increase of SAPK activity which returned to basal within one hour. These data indicate that SAPK activity is the earliest and best correlated cellular marker associated with secretagogue-induced pancreatitis.

Persistent Fluctuations in Stride Intervals under Fractal Auditory Stimulation

PubMed Central

Marmelat, Vivien; Torre, Kjerstin; Beek, Peter J.; Daffertshofer, Andreas

2014-01-01

Stride sequences of healthy gait are characterized by persistent long-range correlations, which become anti-persistent in the presence of an isochronous metronome. The latter phenomenon is of particular interest because auditory cueing is generally considered to reduce stride variability and may hence be beneficial for stabilizing gait. Complex systems tend to match their correlation structure when synchronizing. In gait training, can one capitalize on this tendency by using a fractal metronome rather than an isochronous one? We examined whether auditory cues with fractal variations in inter-beat intervals yield similar fractal inter-stride interval variability as isochronous auditory cueing in two complementary experiments. In Experiment 1, participants walked on a treadmill while being paced by either an isochronous or a fractal metronome with different variation strengths between beats in order to test whether participants managed to synchronize with a fractal metronome and to determine the necessary amount of variability for participants to switch from anti-persistent to persistent inter-stride intervals. Participants did synchronize with the metronome despite its fractal randomness. The corresponding coefficient of variation of inter-beat intervals was fixed in Experiment 2, in which participants walked on a treadmill while being paced by non-isochronous metronomes with different scaling exponents. As expected, inter-stride intervals showed persistent correlations similar to self-paced walking only when cueing contained persistent correlations. Our results open up a new window to optimize rhythmic auditory cueing for gait stabilization by integrating fractal fluctuations in the inter-beat intervals. PMID:24651455

Impact of innate and environmental factors on wheezing persistence during childhood.

PubMed

Just, Jocelyne; Belfar, Samira; Wanin, Stéphanie; Pribil, Céline; Grimfeld, Alain; Duru, Gérard

2010-05-01

Persistent asthma in adults starts often early in childhood and is associated with alterations in respiratory function that occur early in life. The aim of this study was to evaluate the importance of innate and environmental factors associated with occurrence of asthma during childhood in a population of recurrent wheezing infants followed prospectively. A cohort of infants less than 30 months old with recurrent wheezing was established in order to assess severity of respiratory symptoms and to look for the presence of atopy and environmental risk factors. At the age of 6 years, they were reevaluated with respect to remission or persistence of wheezing over the previous 12-month period. Data were available for 219 subjects aged 15 +/- 5 months. In 27% of the infants with recurrent wheeze, wheezing persisted until the age of 6 years. In multivariate analysis, stepwise logit analysis showed that the risk factors for persistent wheezing are eosinophilia >or=470/mm(3), allergenic sensitization, and a father with asthma. Environmental factors present during the first year of life that protect from persistence of wheezing are ( 1 ) breastfeeding for longer than 3 months, ( 2 ) pets at home, and ( 3 ) >or=3 siblings. The detection rate for persistent wheezing in this model is 72%. The persistence score showed good specificity 91% but low sensitivity 35%. This study confirms the role of atopic host factors on wheezing persistence during childhood and detected protective environmental factors.

Does persisting fear sustain catatonia?

PubMed

Fink, M; Shorter, E

2017-11-01

To examine the psychological substrate of catatonia. Reviewing the historical descriptions and explanations of catatonic behaviours by clinicians from its delineation in the 19th century to the present. Patients with catatonia are often haunted by fears and terrors; this has not been widely appreciated, and certainly was lost from view in the days when catatonia was considered a subtype of schizophrenia. The report contributes to resolving a major question in catatonia: is the mind in stupor inactive, as the blank state that we picture in anesthetized patients, or is the mind active, so preoccupied as to exclude all other influences. Persistent fear occupies the mind of catatonic patients. The signs of catatonia are adaptations to persistent fear, akin to tonic immobilization. The relief afforded by sedation supports this interpretation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A Very Persistent Mistake

ERIC Educational Resources Information Center

McClelland, J. A. G.

2011-01-01

Articulated bodies with an internal energy source require to be coupled to an external mass in order to accelerate themselves but the typical text book assertion that the net force is provided by the external mass is not correct. Arguments are presented demonstrating that the assertion is incorrect and reasons are suggested for the persistence of…

Persistence of poultry associated Salmonella spp. on spinach plants

USDA-ARS?s Scientific Manuscript database

Introduction: Pre-harvest spinach contamination can occur via irrigation water and can influence the persistence of Salmonella on spinach leaves. Salmonella persistence on spinach plants should be evaluated as nearby poultry farms can be a critical source of contaminated water run-off. Purpose: The...

Hemocytes Are Sites of Enteric Virus Persistence within Oysters ▿

PubMed Central

Provost, Keleigh; Dancho, Brooke A.; Ozbay, Gulnihal; Anderson, Robert S.; Richards, Gary P.; Kingsley, David H.

2011-01-01

The goal of this study was to determine how enteric viruses persist within shellfish tissues. Several lines of novel evidence show that phagocytic blood cells (hemocytes) of Eastern oysters (Crassostrea virginica) play an important role in the retention of virus particles. Our results demonstrated an association of virus contamination with hemocytes but not with hemolymph. Live oysters contaminated overnight with hepatitis A virus (HAV) and murine norovirus (MNV) had 56% and 80% of extractable virus associated with hemocytes, respectively. Transfer of HAV-contaminated hemocytes to naïve (virus-free) oysters resulted in naïve oyster meat testing HAV positive for up to 3 weeks. Acid tolerance of HAV, MNV, poliovirus (PV), and feline calicivirus (FCV) correlated with the ability of each virus to persist within oysters. Using reverse transcription-PCR (RT-PCR) to evaluate persistence of these viruses in oysters, we showed that HAV persisted the longest (>21 days) and was most acid resistant, MNV and PV were less tolerant of acidic pH, persisting for up to 12 days and 1 day, respectively, and FCV did not persist (<1 day) within oysters and was not acid tolerant. This suggests that the ability of a virus to tolerate the acidic conditions typical of phagolysosomal vesicles within hemocytes plays a role in determining virus persistence in shellfish. Evaluating oyster and hemocyte homogenates and live contaminated oysters as a prelude to developing improved viral RNA extraction methods, we found that viruses were extracted more expediently from hemocytes than from whole shellfish tissues and gave similar RT-PCR detection sensitivities. PMID:21948840

Persistent and Repetitive Visual Disturbances in Migraine: A Review.

PubMed

Schankin, Christoph J; Viana, Michele; Goadsby, Peter J

2017-01-01

Visual disturbances in migraineurs, such as visual aura, are typically episodic, that is, associated with the headache attack, and overlaid by head pain and other symptoms that impact the patient. In some patients, however, visual symptoms are dominant due to frequency (migraine aura status), duration (persistent migraine aura and other persistent positive visual phenomena), or complexity (visual snow syndrome). These syndromes are more rare and challenging to classify in clinical practice resulting in a lack of systematic studies on pathophysiology and treatment. We aim at describing clinical features and pathophysiological concepts of typical migraine aura with a focus on cortical spreading depression and differentiation from non-typical migraine aura. Additionally, we discuss nomenclature and the specifics of migraine aura status, persistent migraine aura, persistent positive visual phenomena, visual snow, and other migrainous visual disturbances. The term migraine with prolonged aura might be a useful bridge between typical aura and persistent aura. Further studies would be necessary to assess whether a return of the classification category eventually helps diagnosing or treating patients more effectively. A practical approach is presented to help the treating physician to assign the correct diagnosis and to choose a medication for treatment that has been successful in case reports of these rare but disabling conditions. © 2016 American Headache Society.

Anxiety in speakers who persist and recover from stuttering.

PubMed

Davis, Stephen; Shisca, Daniella; Howell, Peter

2007-01-01

The study was designed to see whether young children and adolescents who persist in their stutter (N=18) show differences in trait and/or state anxiety compared with people who recover from their stutter (N=17) and fluent control speakers (N=19). A fluent control group, a group of speakers who have been documented as stuttering in the past but do not stutter now and a group of speakers (also with a documented history of stuttering) who persist in their stuttering participated, all aged 10-17 years. The State-Trait Anxiety Inventory for Children was administered. There were no differences between persistent, recovered and control groups with regard to trait anxiety. The persistent group had higher state anxiety than controls and the recovered group for three out of four speaking situations. The findings are interpreted as showing that anxiety levels in certain affective states appear to be associated with the speaking problem. A reader should be able to appreciate the difference between state and trait anxiety understand views about how the role anxiety has on stuttering has changed over time appreciate different views about how anxiety affects speakers who persist and recover from stuttering see why longitudinal work is needed to study these issues.

Differences in the mechanism of inoculation between a semi-persistent and a non-persistent aphid-transmitted plant virus.

PubMed

Moreno, Aranzazu; Tjallingii, W Freddy; Fernandez-Mata, Gabriela; Fereres, Alberto

2012-03-01

Inoculation of the semi-persistent cauliflower mosaic virus (CaMV, genus Caulimovirus) is associated with successive brief (5-10 s) intracellular stylet punctures (pd) when aphids probe in epidermal and mesophyll cells. In contrast to non-persistent viruses, there is no evidence for which of the pd subphases (II-1, II-2 and II-3) is involved in the inoculation of CaMV. Experiments were conducted using the electrical penetration graph (EPG) technique to investigate which particular subphases of the pd are associated with the inoculation of CaMV to turnip by its aphid vector Brevicoryne brassicae. In addition, the same aphid species/test plant combination was used to compare the role of the pd subphases in the inoculation of the non-persistent turnip mosaic virus (TuMV, genus Potyvirus). Inoculation of TuMV was found to be related to subphase II-1, confirming earlier results, but CaMV inoculation appeared to be related exclusively to subphase II-2 instead. The mechanism of CaMV inoculation and the possible nature of subphase II-2 are discussed in the scope of our findings.

Identification of the earliest collagen- and plant-based coatings from Neolithic artefacts (Nahal Hemar cave, Israel).

PubMed

Solazzo, Caroline; Courel, Blandine; Connan, Jacques; van Dongen, Bart E; Barden, Holly; Penkman, Kirsty; Taylor, Sheila; Demarchi, Beatrice; Adam, Pierre; Schaeffer, Philippe; Nissenbaum, Arie; Bar-Yosef, Ofer; Buckley, Michael

2016-08-09

Mortuary practices in human evolution record cognitive, social changes and technological innovations. The Neolithic Revolution in the Levant was a watershed in this domain that has long fascinated the archaeological community. Plaster modelled skulls are well known at Jericho and several other Neolithic sites, and in Nahal Hemar cave (Israel, ca. 8200 -7300 cal. BC) excavations yielded six unique human skulls covered with a black organic coating applied in a net pattern evoking a headdress. This small cave was used as storage for paraphernalia in the semi-arid area of the Judean desert and the dry conditions preserved other artefacts such as baskets coated with a similar dark substance. While previous analysis had revealed the presence of amino acids consistent with a collagen signature, in the present report, specific biomarkers were characterised using combined proteomic and lipid approaches. Basket samples yielded collagen and blood proteins of bovine origin (Bos genus) and a large sequence coverage of a plant protein charybdin (Charybdis genus). The skull residue samples were dominated by benzoate and cinnamate derivatives and triterpenes consistent with a styrax-type resin (Styrax officinalis), thus providing the earliest known evidence of an odoriferous plant resin used in combination with an animal product.

New dinosaur (Theropoda, stem-Averostra) from the earliest Jurassic of the La Quinta formation, Venezuelan Andes

PubMed Central

Langer, Max C.; Rincón, Ascanio D.; Ramezani, Jahandar; Solórzano, Andrés; Rauhut, Oliver W. M.

2014-01-01

Dinosaur skeletal remains are almost unknown from northern South America. One of the few exceptions comes from a small outcrop in the northernmost extension of the Andes, along the western border of Venezuela, where strata of the La Quinta Formation have yielded the ornithischian Laquintasaura venezuelae and other dinosaur remains. Here, we report isolated bones (ischium and tibia) of a small new theropod, Tachiraptor admirabilis gen. et sp. nov., which differs from all previously known members of the group by an unique suite of features of its tibial articulations. Comparative/phylogenetic studies place the new form as the sister taxon to Averostra, a theropod group that is known primarily from the Middle Jurassic onwards. A new U–Pb zircon date (isotope dilution thermal-ionization mass spectrometry; ID-TIMS method) from the bone bed matrix suggests an earliest Jurassic maximum age for the La Quinta Formation. A dispersal–vicariance analysis suggests that such a stratigraphic gap is more likely to be filled by new records from north and central Pangaea than from southern areas. Indeed, our data show that the sampled summer-wet equatorial belt, which yielded the new taxon, played a pivotal role in theropod evolution across the Triassic–Jurassic boundary. PMID:26064540

Identification of the earliest collagen- and plant-based coatings from Neolithic artefacts (Nahal Hemar cave, Israel)

PubMed Central

Solazzo, Caroline; Courel, Blandine; Connan, Jacques; van Dongen, Bart E.; Barden, Holly; Penkman, Kirsty; Taylor, Sheila; Demarchi, Beatrice; Adam, Pierre; Schaeffer, Philippe; Nissenbaum, Arie; Bar-Yosef, Ofer; Buckley, Michael

2016-01-01

Mortuary practices in human evolution record cognitive, social changes and technological innovations. The Neolithic Revolution in the Levant was a watershed in this domain that has long fascinated the archaeological community. Plaster modelled skulls are well known at Jericho and several other Neolithic sites, and in Nahal Hemar cave (Israel, ca. 8200 −7300 cal. BC) excavations yielded six unique human skulls covered with a black organic coating applied in a net pattern evoking a headdress. This small cave was used as storage for paraphernalia in the semi-arid area of the Judean desert and the dry conditions preserved other artefacts such as baskets coated with a similar dark substance. While previous analysis had revealed the presence of amino acids consistent with a collagen signature, in the present report, specific biomarkers were characterised using combined proteomic and lipid approaches. Basket samples yielded collagen and blood proteins of bovine origin (Bos genus) and a large sequence coverage of a plant protein charybdin (Charybdis genus). The skull residue samples were dominated by benzoate and cinnamate derivatives and triterpenes consistent with a styrax-type resin (Styrax officinalis), thus providing the earliest known evidence of an odoriferous plant resin used in combination with an animal product. PMID:27503740

New dinosaur (Theropoda, stem-Averostra) from the earliest Jurassic of the La Quinta formation, Venezuelan Andes.

PubMed

Langer, Max C; Rincón, Ascanio D; Ramezani, Jahandar; Solórzano, Andrés; Rauhut, Oliver W M

2014-10-01

Dinosaur skeletal remains are almost unknown from northern South America. One of the few exceptions comes from a small outcrop in the northernmost extension of the Andes, along the western border of Venezuela, where strata of the La Quinta Formation have yielded the ornithischian Laquintasaura venezuelae and other dinosaur remains. Here, we report isolated bones (ischium and tibia) of a small new theropod, Tachiraptor admirabilis gen. et sp. nov., which differs from all previously known members of the group by an unique suite of features of its tibial articulations. Comparative/phylogenetic studies place the new form as the sister taxon to Averostra, a theropod group that is known primarily from the Middle Jurassic onwards. A new U-Pb zircon date (isotope dilution thermal-ionization mass spectrometry; ID-TIMS method) from the bone bed matrix suggests an earliest Jurassic maximum age for the La Quinta Formation. A dispersal-vicariance analysis suggests that such a stratigraphic gap is more likely to be filled by new records from north and central Pangaea than from southern areas. Indeed, our data show that the sampled summer-wet equatorial belt, which yielded the new taxon, played a pivotal role in theropod evolution across the Triassic-Jurassic boundary.

Ceftaroline as Salvage Monotherapy for Persistent MRSA Bacteremia.

PubMed

Burnett, Yvonne J; Echevarria, Kelly; Traugott, Kristi A

2016-12-01

To summarize published data regarding the use of ceftaroline as salvage monotherapy for persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. PubMed (January 1980-June 2016) was searched using combinations of the search terms methicillin-resistant Staphylococcus aureus, MRSA, bacteremia, ceftaroline, refractory, and persistent Supplemental references were generated through review of identified literature citations. Available English-language, full-text articles pertaining to the use of ceftaroline for persistent MRSA bacteremia (MRSAB) were included. The PubMed search yielded 23 articles for evaluation. There are no randomized controlled trials to date-only case series and reports. Four retrospective case series detailing the use of ceftaroline as monotherapy for persistent MRSAB were included. Most patients received at least 4 days of an appropriate anti-MRSA antimicrobial prior to ceftaroline and were able to clear bacteremia within 3 days. The most common rationales for ceftaroline use were progression of disease or nonresponse to current therapy. Higher off-label dosing of ceftaroline is often utilized to achieve optimal pharmacokinetic/pharmacodynamic parameters. Adverse events are not well described due to lack of follow-up; however, neutropenia has been associated with prolonged use. Treatment options for persistent MRSAB remain few and far between. Ceftaroline is an effective agent for the salvage treatment of MRSAB. Off-label doses up to 600 mg every 8 hours are often used to achieve optimal pharmacokinetic/pharmacodynamic parameters. Because of lack of follow-up in these reports, the incidence of adverse effects of prolonged use of ceftaroline is not well defined. © The Author(s) 2016.

Persistence of Salmonid Redds

NASA Astrophysics Data System (ADS)

Buffington, J. M.; Buxton, T.; Fremier, A. K.; Hassan, M. A.; Yager, E.

2013-12-01

The construction of redds by spawning salmonids modifies fluvial processes in ways that are beneficial to egg and embryo survival. Redd topography induces hyporheic flow that oxygenates embryos incubating within the streambed and creates form drag that reduces bed mobility and scour of salmonid eggs. Winnowing of fine material during redd construction also coarsens the streambed, increasing bed porosity and hyporheic flow and reducing bed mobility. In addition to the biological benefits, redds may influence channel morphology by altering channel hydraulics and bed load transport rates depending on the size and extent of redds relative to the size of the channel. A key question is how long do the physical and biological effects of redds last? Field observations indicate that in some basins redds are ephemeral, with redd topography rapidly erased by subsequent floods, while in other basins, redds can persist for years. We hypothesize that redd persistence is a function of basin hydrology, sediment supply, and characteristics of the spawning fish. Hydrology controls the frequency and magnitude of bed mobilizing flows following spawning, while bed load supply (volume and caliber) controls the degree of textural fining and consequent bed mobility after spawning, as well as the potential for burial of redd features. The effectiveness of flows in terms of their magnitude and duration depend on hydroclimate (i.e., snowmelt, rainfall, or transitional hydrographs), while bed load supply depends on basin geology, land use, and natural disturbance regimes (e.g., wildfire). Location within the stream network may also influence redd persistence. In particular, lakes effectively trap sediment and regulate downstream flow, which may promote long-lived redds in stream reaches below lakes. These geomorphic controls are modulated by biological factors: fish species (size of fish controls size of redds and magnitude of streambed coarsening); life history (timing of spawning and

Immunomodulation by Persistent Organic Pollutants

EPA Science Inventory

Persistent organic pollutants (POPs) are widely distnbuted in the environment, are resistant to degradation, and increase in concentration (biomagnify) in the food chain. Concentrations in apical predators may be tens to hundreds of times greater than concentrations in their pref...

What about Master's Students? The Master's Student Persistence Model

ERIC Educational Resources Information Center

Cohen, Kristin E.

2012-01-01

This study was designed to investigate the factors that affect master's student persistence in the United States. More specifically, this study explored whether the following factors: students' background, institution's, academic, environmental and psychological influences, had a significant effect on whether a master's student persisted and/or…

Diabetes is associated with persistent pain after hip and knee replacement

PubMed Central

Rajamäki, Tuomas J; Jämsen, Esa; Puolakka, Pia A; Nevalainen, Pasi I; Moilanen, Teemu

2015-01-01

Background and purpose In some patients, for unknown reasons pain persists after joint replacement, especially in the knee. We determined the prevalence of persistent pain following primary hip or knee replacement and its association with disorders of glucose metabolism, metabolic syndrome (MetS), and obesity. Patients and methods The incidence of pain in the operated joint was surveyed 1–2 years after primary hip replacement (74 patients (4 bilateral)) or primary knee replacement (119 patients (19 bilateral)) in 193 osteoarthritis patients who had participated in a prospective study on perioperative hyperglycemia. Of the 155 patients who completed the survey, 21 had undergone further joint replacement surgery during the follow-up and were excluded, leaving 134 patients for analysis. Persistent pain was defined as daily pain in the operated joint that had lasted over 3 months. Factors associated with persistent pain were evaluated using binary logistic regression with adjustment for age, sex, and operated joint. Results 49 of the134 patients (37%) had a painful joint and 18 of them (14%) had persistent pain. A greater proportion of knee patients than hip patients had a painful joint (46% vs. 24%; p = 0.01) and persistent pain (20% vs. 4%; p = 0.007). Previously diagnosed diabetes was strongly associated with persistent pain (5/19 vs. 13/115 in those without; adjusted OR = 8, 95% CI: 2–38) whereas MetS and obesity were not. However, severely obese patients (BMI ≥ 35) had a painful joint (but not persistent pain) more often than patients with BMI < 30 (14/21 vs. 18/71; adjusted OR = 5, 95% CI: 2–15). Interpretation Previously diagnosed diabetes is a risk factor for persistent pain in the operated joint 1–2 years after primary hip or knee replacement. PMID:25953426

Predicting Undergraduates' Persistence in Science, Technology, Engineering, and Math Fields

NASA Astrophysics Data System (ADS)

Koch, Amanda Joy

A national shortage of workers in Science, Technology, Engineering, and Math (STEM) occupations has led to efforts to identify why people leave these fields. Lower persistence rates in STEM for females than for males have also led to examinations of features that cause females to leave STEM fields. The current study examines individual- and school-level features that influence undergraduate students' decisions to leave STEM majors, focusing on potential explanations for why females are more likely than males to leave. Persistence in STEM was examined in three samples: (a) persistence through the second year of college in a sample of high school seniors interested in STEM majors; (b) persistence through the fourth year of college in a sample of second year undergraduate STEM majors; and (c) persistence through the second, third, and fourth years of college in a sample of high school seniors interested in STEM majors. Differences between persistence in male-dominated and non-male-dominated STEM majors were also examined. In all samples, gender differences were found for most individual-level predictors, with males tending to score higher than females on measures such as SAT-Math, self-rated STEM ability, and high school extracurricular activities and awards in STEM. On the other hand, females earned better high school grades and had stronger relative non-STEM ability and achievement than males. Bivariate analyses indicated that those who persisted in STEM majors typically had higher scores than those who did not persist for SAT-Math, high school achievement, STEM course taking, undergraduate STEM grades, self-rated STEM ability, interest in STEM, extracurricular activities and awards in STEM, degree goals, and socioeconomic status. Multivariate analyses identified SAT-Math as one of the best predictors of persistence in high school samples, and undergraduate STEM GPA was one of the best predictors in the samples of second year undergraduates. In several samples, a

Injury patterns in clashes between citizens and security forces during forced evacuation.

PubMed

Schwartz, D; Bar-Dayan, Y

2008-10-01

Clashes between state security forces and civilian populations can lead to mass casualty incidents (MCI), challenging emergency medical service (EMS) systems, hospitals and medical management systems. In January 2006, clashes erupted between Israeli security forces and settlers, around the forced evacuation of the Amona outpost. Data collected during the events and in subsequent formal debriefings were processed to identify the specifics of an MCI caused by forced evacuation. Pre-event preparedness, time and types of injuries encountered were evaluated among evacuated civilians and security forces members, their transport to hospitals, care received and follow-up. The event is described according to DISAST-CIR methodology. Data were entered on MS Excel (2003) and analysis was carried out using SPSS version 12. 4000 police personnel (backed by army forces) clashed for 12 h with approximately 5000 settlers. 229 injured (174 settlers and 55 security personnel) were cared for at six receiving hospitals. A total of 16 were evacuated by aeromedical evacuation, including one severely head-injured policeman. Settlers used sticks, stones and cement blocks, whereas police used mounted riders, batons and shields. Head injuries were the most common injuries among settlers (50%), whereas extremity injuries dominated among security forces members (72.7%). Large-scale clashes between state security forces and citizens may cause numerous injuries, even if firearms and explosives are not used. Despite the fact that almost all injuries were mild, the incident burdened local medical teams, EMS and Jerusalem hospitals. A predominance of head injuries was found among injured settlers and extremity injuries among injured security forces.

Environmental reservoirs and mechanisms of persistence of Vibrio cholerae

PubMed Central

Lutz, Carla; Erken, Martina; Noorian, Parisa; Sun, Shuyang; McDougald, Diane

2013-01-01

It is now well accepted that Vibrio cholerae, the causative agent of the water-borne disease cholera, is acquired from environmental sources where it persists between outbreaks of the disease. Recent advances in molecular technology have demonstrated that this bacterium can be detected in areas where it has not previously been isolated, indicating a much broader, global distribution of this bacterium outside of endemic regions. The environmental persistence of V. cholerae in the aquatic environment can be attributed to multiple intra- and interspecific strategies such as responsive gene regulation and biofilm formation on biotic and abiotic surfaces, as well as interactions with a multitude of other organisms. This review will discuss some of the mechanisms that enable the persistence of this bacterium in the environment. In particular, we will discuss how V. cholerae can survive stressors such as starvation, temperature, and salinity fluctuations as well as how the organism persists under constant predation by heterotrophic protists. PMID:24379807

Coupling effect of nodes popularity and similarity on social network persistence

PubMed Central

Jin, Xiaogang; Jin, Cheng; Huang, Jiaxuan; Min, Yong

2017-01-01

Network robustness represents the ability of networks to withstand failures and perturbations. In social networks, maintenance of individual activities, also called persistence, is significant towards understanding robustness. Previous works usually consider persistence on pre-generated network structures; while in social networks, the network structure is growing with the cascading inactivity of existed individuals. Here, we address this challenge through analysis for nodes under a coevolution model, which characterizes individual activity changes under three network growth modes: following the descending order of nodes’ popularity, similarity or uniform random. We show that when nodes possess high spontaneous activities, a popularity-first growth mode obtains highly persistent networks; otherwise, with low spontaneous activities, a similarity-first mode does better. Moreover, a compound growth mode, with the consecutive joining of similar nodes in a short period and mixing a few high popularity nodes, obtains the highest persistence. Therefore, nodes similarity is essential for persistent social networks, while properly coupling popularity with similarity further optimizes the persistence. This demonstrates the evolution of nodes activity not only depends on network topology, but also their connective typology. PMID:28220840

Relations between Preschool Attention Span-Persistence and Age 25 Educational Outcomes.

PubMed

McClelland, Megan M; Acock, Alan C; Piccinin, Andrea; Rhea, Sally Ann; Stallings, Michael C

2013-04-01

This study examined relations between children's attention span-persistence in preschool and later school achievement and college completion. Children were drawn from the Colorado Adoption Project using adopted and non-adopted children ( N = 430). Results of structural equation modeling indicated that children's age 4 attention span-persistence significantly predicted math and reading achievement at age 21 after controlling for achievement levels at age 7, adopted status, child vocabulary skills, gender, and maternal education level. Relations between attention span-persistence and later achievement were not fully mediated by age 7 achievement levels. Logistic regressions also revealed that age 4 attention span-persistence skills significantly predicted the odds of completing college by age 25. The majority of this relationship was direct and was not significantly mediated by math or reading skills at age 7 or age 21. Specifically, children who were rated one standard deviation higher on attention span-persistence at age 4 had 48.7% greater odds of completing college by age 25. Discussion focuses on the importance of children's early attention span-persistence for later school achievement and educational attainment.

Coupling effect of nodes popularity and similarity on social network persistence

NASA Astrophysics Data System (ADS)

Jin, Xiaogang; Jin, Cheng; Huang, Jiaxuan; Min, Yong

2017-02-01

Network robustness represents the ability of networks to withstand failures and perturbations. In social networks, maintenance of individual activities, also called persistence, is significant towards understanding robustness. Previous works usually consider persistence on pre-generated network structures; while in social networks, the network structure is growing with the cascading inactivity of existed individuals. Here, we address this challenge through analysis for nodes under a coevolution model, which characterizes individual activity changes under three network growth modes: following the descending order of nodes’ popularity, similarity or uniform random. We show that when nodes possess high spontaneous activities, a popularity-first growth mode obtains highly persistent networks; otherwise, with low spontaneous activities, a similarity-first mode does better. Moreover, a compound growth mode, with the consecutive joining of similar nodes in a short period and mixing a few high popularity nodes, obtains the highest persistence. Therefore, nodes similarity is essential for persistent social networks, while properly coupling popularity with similarity further optimizes the persistence. This demonstrates the evolution of nodes activity not only depends on network topology, but also their connective typology.

Coupling effect of nodes popularity and similarity on social network persistence.

PubMed

Jin, Xiaogang; Jin, Cheng; Huang, Jiaxuan; Min, Yong

2017-02-21

Network robustness represents the ability of networks to withstand failures and perturbations. In social networks, maintenance of individual activities, also called persistence, is significant towards understanding robustness. Previous works usually consider persistence on pre-generated network structures; while in social networks, the network structure is growing with the cascading inactivity of existed individuals. Here, we address this challenge through analysis for nodes under a coevolution model, which characterizes individual activity changes under three network growth modes: following the descending order of nodes' popularity, similarity or uniform random. We show that when nodes possess high spontaneous activities, a popularity-first growth mode obtains highly persistent networks; otherwise, with low spontaneous activities, a similarity-first mode does better. Moreover, a compound growth mode, with the consecutive joining of similar nodes in a short period and mixing a few high popularity nodes, obtains the highest persistence. Therefore, nodes similarity is essential for persistent social networks, while properly coupling popularity with similarity further optimizes the persistence. This demonstrates the evolution of nodes activity not only depends on network topology, but also their connective typology.

Spatial Variations in Drought Persistence in the South-Central U.S.

NASA Astrophysics Data System (ADS)

Leasor, Z. T.; Quiring, S. M.

2016-12-01

Drought is one of the most prominent climatic hazards in the south-central United States. This study examines spatial variations in meteorological drought persistence using high-resolution PRISM gridded precipitation data from 1900-2015. The Standardized Precipitation Index (SPI) is used to represent meteorological drought conditions. The study region covers Texas, Oklahoma, and Kansas. Droughts are first divided into different severity categories using the classification employed by the U.S. National Drought Monitor. The frequency and duration of each drought event is determined and this is used to calculate drought persistence. Our results indicate that drought persistence in the south-central U.S. varies as a function of drought severity. In addition, drought persistence also varies substantially over space and time. The probability of drought termination is a function of drought severity, geographic location and time of the year. In addition, there is evidence that drought persistence is influenced by global teleconnections and land-atmosphere interactions. The results of this drought persistence climatology can benefit seasonal forecasting and the current understanding of drought recovery.

Cutoffs, Norms, and Patterns of Problem Behaviors in Children with an ASD on the Baby and Infant Screen for Children with aUtIsm Traits (BISCUIT-Part 3)

ERIC Educational Resources Information Center

Rojahn, Johannes; Matson, Johnny L.; Mahan, Sara; Fodstad, Jill C.; Knight, Cheryl; Sevin, Jay A.; Sharp, Brenda

2009-01-01

Challenging behaviors are common and persistent in persons with autism spectrum disorders (ASDs). Best practices dictate that symptoms of ASD and these co-occurring problems be identified and then treated at the earliest possible age. Having said this, there has been a dearth of available assessment methods to make sure identifications in infants…

Strategies used by helicobacter pylori to establish persistent infection

PubMed Central

Abadi, Amin Talebi Bezmin

2017-01-01

Helicobacter pylori (H. pylori) is a Gram-negative and motile bacterium that colonizes the hostile microniche of the human stomach, then persists for the host’s entire life, if not effectively treated. Clinically, H. pylori plays a causative role in the development of a wide spectrum of diseases including chronic active gastritis, peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Due to the global distribution of H. pylori, it is no exaggeration to conclude that smart strategies are contributing to adaptation of the bacterium to its permanent host. Thirty-four years after the discovery of this bacterium, there are still many unanswered questions. For example, which strategies help the bacterium to survive in this inhospitable microniche? This question is slightly easier to answer if we presume the same clinical concept for both persistent infection and disease. Understanding the mechanisms governing H. pylori persistence will improve identification of the increased risk of diseases such as gastric cancer in patients infected with this bacterium. A well-defined and long-term equilibrium between the human host and H. pylori allows bacterial persistence in the gastric microniche; although this coexistence leads to a high risk of severe diseases such as gastric cancer. To escape the bactericidal activity of stomach acid, H. pylori secretes large amounts of surface-associated and cytosolic urease. The potential to avoid acidic conditions and immune evasion are discussed in order to explain the persistence of H. pylori colonization in the gastric mucosa, and data on bacterial genetic diversity are included. Information on the mechanisms related to H. pylori persistence can also provide the direction for future research concerning effective therapy and management of gastroduodenal disorders. The topics presented in the current review are important for elucidating the strategies used by H. pylori to help the bacterium

Clinical and prognostic subforms of new daily-persistent headache

PubMed Central

Grosberg, B.M.; Napchan, U.; Crystal, S.C.; Lipton, R.B.

2010-01-01

Background: According to the International Classification of Headache Disorders (ICHD)–2, primary daily headaches unremitting from onset are classified as new daily-persistent headache (NDPH) only if migraine features are absent. When migraine features are present, classification is problematic. Methods: We developed a revised NDPH definition not excluding migraine features (NDPH-R), and applied it to consecutive patients seen at the Montefiore Headache Center. We divided this group into patients meeting ICHD-2 criteria (NDPH-ICHD) and those with too many migraine features for ICHD-2 (NDPH-mf). We compared clinical and demographic features in these groups, identifying 3 prognostic subgroups: persisting, remitting, and relapsing-remitting. Remitting and relapsing-remitting patients were combined into a nonpersisting group. Results: Of 71 NDPH-R patients, 31 (43.7%) also met NDPH-ICHD-2 criteria. The NDPH-mf and the NDPH-ICHD-2 groups were similar in most clinical features though the NDPH-mf group was younger, included more women, and had a higher frequency of depression. The groups were similar in the prevalence of allodynia, triptan responsiveness, and prognosis. NDPH-R prognostic subforms were also very similar, although the persisting subform was more likely to be of white race, to have anxiety or depression, and to have a younger onset age. Conclusions: Current International Classification of Headache Disorders (ICHD)–2 criteria exclude the majority of patients with primary headache unremitting from onset. The proposed criteria for revised new daily-persistent headache definition not excluding migraine features (NDPH-R) classify these patients into a relatively homogeneous group based on demographics, clinical features, and prognosis. Both new daily-persistent headache with too many migraine features for ICHD-2 and new daily-persistent headache meeting ICHD-2 criteria include patients in equal proportions that fall into the persisting, remitting, and

June 2017: The Earliest European Summer Mega-heatwave of Reanalysis Period

NASA Astrophysics Data System (ADS)

Sánchez-Benítez, A.; García-Herrera, R.; Barriopedro, D.; Sousa, P. M.; Trigo, R. M.

2018-02-01

This paper examines the characteristics of the heatwave that affected western and central Europe in June 2017. Using a novel algorithm, we show that its extension, intensity, and persistence were comparable to those of other European mega-heatwaves, but it occurred earlier in the summer. The most affected area was Iberia, which experienced devastating forest fires with human casualties and the warmest temperatures of the reanalysis period from daily to seasonal scales. The peak of the mega-heatwave displayed an unprecedented warm air intrusion due to a record-breaking subtropical ridge with signatures closer to those of July and August. The atmospheric circulation was the main triggering factor of the event. However, thermodynamical changes of the last decades made a substantial contribution to the event, by increasing the likelihood of surpassing high-temperature thresholds. This episode could be a good example of a coming future, with high-summer mega-heatwaves occurring earlier.

Variants of human papillomavirus type 16 predispose toward persistent infection

PubMed Central

Zhang, Lei; Liao, Hong; Yang, Binlie; Geffre, Christopher P; Zhang, Ai; Zhou, Aizhi; Cao, Huimin; Wang, Jieru; Zhang, Zhenbo; Zheng, Wenxin

2015-01-01

A cohort study of 292 Chinese women was conducted to determine the relationship between human papillomavirus (HPV) type 16 variants and persistent viral infection. Enrolled patients were HPV16 positive and had both normal cytology and histology. Flow-through hybridization and gene chip technology was used to identify the HPV type. A PCR sequencing assay was performed to find HPV16 E2, E6 and E7 gene variants. The associations between these variants and HPV16 persistent infection was analyzed by Fisher’s exact test. It was found that the variants T178G, T350G and A442C in the E6 gene, as well as C3158A and G3248A variants in the E2 gene were associated with persistent HPV16 infection. No link was observed between E7 variants and persistent viral infection. Our findings suggest that detection of specific HPV variants would help identify patients who are at high risk for viral persistence and development of cervical neoplasia. PMID:26339417

An Updated Global Picture of Cigarette Smoking Persistence among Adults

PubMed Central

Troost, Jonathan P.; Barondess, David A.; Storr, Carla L.; Wells, J. Elisabeth; Al-Hamzawi, Ali Obaid; Andrade, Laura Helena; Bromet, Evelyn; Bruffaerts, Ronny; Florescu, Silvia; de Girolamo, Giovanni; de Graaf, Ron; Gureje, Oye; Haro, Josep Maria; Hu, Chiyi; Huang, Yueqin; Karam, Aimee N.; Kessler, Ronald C.; Lepine, Jean-Pierre; Matschinger, Herbert; Medina-Mora, Maria Elena; O'Neill, Siobhan; Posada-Villa, Jose; Sagar, Rajesh; Takeshima, Tadashi; Tomov, Toma; Williams, David R.; Anthony, James C.

2012-01-01

Background Cross-national variance in smoking prevalence is relatively well documented. The aim of this study is to estimate levels of smoking persistence across 21 countries with a hypothesized inverse relationship between country income level and smoking persistence. Methods Data from the World Health Organization World Mental Health Survey Initiative were used to estimate cross-national differences in smoking persistence–the proportion of adults who started to smoke and persisted in smoking by the date of the survey. Result There is large variation in smoking persistence from 25% (Nigeria) to 85% (China), with a random-effects meta-analytic summary estimate of 55% with considerable cross-national variation. (Cochran's heterogeneity Q statistic=6,845; p<0.001). Meta-regressions indicated observed differences are not attributable to differences in country income level, age distribution of smokers, or how recent the onset of smoking began within each country. Conclusion While smoking should remain an important public health issue in any country where smokers are present, this report identifies several countries with higher levels of smoking persistence (namely, China and India). PMID:23626929

Secondary Science Teachers' Beliefs and Persistence: A Longitudinal Mixed-Methods Study

ERIC Educational Resources Information Center

Wong, Sissy S.; Luft, Julie A.

2015-01-01

While many studies focus on why teachers leave the classroom, there remains a need to study why teachers persist in teaching. One area to study is the beliefs of teachers, which may impact persistence in the field. This 5-year mixed-methods study explored whether 35 beginning secondary science teachers' beliefs were related to their persistence in…

Why They Stay: Women Persisting in US Engineering Careers

ERIC Educational Resources Information Center

Buse, Kathleen; Bilimoria, Diana; Perelli, Sheri

2013-01-01

Purpose: Women remain dramatically underrepresented in the engineering profession and far fewer women than men persist in the field. This study aims to identify individual and contextual factors that distinguish women who persist in engineering careers in the US. Design/methodology/approach: Qualitative research was conducted based on…

Moving from Damage-Centered Research through Unsettling Reflexivity

ERIC Educational Resources Information Center

Calderon, Dolores

2016-01-01

The author revisits autoethnographic work in order to examine how she unwittingly incorporated damage-centered (Tuck 2009) research approaches that reproduce settler colonial understandings of marginalized communities. The paper examines the reproduction of settler colonial knowledge in ethnographic research by unearthing the inherent surveillance…

Impact of persistence and non-persistence in leisure time physical activity on coronary heart disease and all-cause mortality: The Copenhagen City Heart Study.

PubMed

Schnohr, Peter; O'Keefe, James H; Lange, Peter; Jensen, Gorm Boje; Marott, Jacob Louis

2017-10-01

Aims The aim of this study was to investigate the impact of persistence and non-persistence in leisure time physical activity on coronary heart disease and all-cause mortality. Methods and results In the Copenhagen City Heart Study, we prospectively followed 12,314 healthy subjects for 33 years of maximum follow-up with at least two repeated measures of physical activity. The association between persistence and non-persistence in leisure time physical activity, coronary heart disease and all-cause mortality were assessed by multivariable Cox regression analyses. Coronary heart disease mortality for persistent physical activity in leisure compared to persistent sedentary activity were: light hazard ratio (HR) 0.76; 95% confidence interval (CI) 0.63-0.92, moderate HR 0.52; 95% CI 0.41-0.67, and high physical activity HR 0.51; 95% CI, 0.30-0.88. The differences in longevity were 2.8 years for light, 4.5 years for moderate and 5.5 years for high physical activity. A substantial increase in physical activity was associated with lower coronary heart disease mortality (HR 0.75; 95% CI 0.52-1.08) corresponding to 2.4 years longer life, whereas a substantial decrease in physical activity was associated with higher coronary heart disease mortality (HR 1.61; 95% CI 1.11-2.33) corresponding to 4.2 years shorter life than the unchanged group. A similar pattern was observed for all-cause mortality. Conclusion We found inverse dose-response relationships between persistent leisure time physical activity and both coronary heart disease and all-cause mortality. A substantial increase in physical activity was associated with a significant gain in longevity, whereas a decrease in physical activity was associated with even greater loss of longevity.

Environmental Persistence Influences Infection Dynamics for a Butterfly Pathogen

PubMed Central

Altizer, Sonia; Williams, Mary-Kate; Hall, Richard J.

2017-01-01

Many pathogens, including those infecting insects, are transmitted via dormant stages shed into the environment, where they must persist until encountering a susceptible host. Understanding how abiotic conditions influence environmental persistence and how these factors influence pathogen spread are crucial for predicting patterns of infection risk. Here, we explored the consequences of environmental transmission for infection dynamics of a debilitating protozoan parasite (Ophryocystis elektroscirrha) that infects monarch butterflies (Danaus plexippus). We first conducted an experiment to observe the persistence of protozoan spores exposed to natural conditions. Experimental results showed that, contrary to our expectations, pathogen doses maintained high infectivity even after 16 days in the environment, although pathogens did yield infections with lower parasite loads after environmental exposure. Because pathogen longevity exceeded the time span of our experiment, we developed a mechanistic model to better explore environmental persistence for this host-pathogen system. Model analysis showed that, in general, longer spore persistence led to higher infection prevalence and slightly smaller monarch population sizes. The model indicated that typical parasite doses shed onto milkweed plants must remain viable for a minimum of 3 weeks for prevalence to increase during the summer-breeding season, and for 11 weeks or longer to match levels of infection commonly reported from the wild, assuming moderate values for parasite shedding rate. Our findings showed that transmission stages of this butterfly pathogen are long-lived and indicated that this is a necessary condition for the protozoan to persist in local monarch populations. This study provides a modeling framework for future work examining the dynamics of an ecologically important pathogen in an iconic insect. PMID:28099501

Post-retrieval late process contributes to persistence of reactivated fear memory.

PubMed

Nakayama, Daisuke; Yamasaki, Yoshiko; Matsuki, Norio; Nomura, Hiroshi

2013-05-16

Several studies have demonstrated the mechanisms involved in memory persistence after learning. However, little is known about memory persistence after retrieval. In this study, a protein synthesis inhibitor, anisomycin, was infused into the basolateral amygdala of mice 9.5 h after retrieval of contextual conditioned fear. Anisomycin attenuated fear memory after 7 d, but not after 2 d. In contrast, infusion of anisomycin 5- or 24-h post-retrieval was ineffective. These findings indicate that anisomycin attenuates the persistence of reactivated fear memory in a time-dependent manner. We propose that late protein synthesis is required for memory persistence after retrieval.

Patients with Long-Term Oral Carriage Harbor High-Persister Mutants of Candida albicans▿

PubMed Central

LaFleur, Michael D.; Qi, Qingguo; Lewis, Kim

2010-01-01

Fungal biofilms produce a small number of persister cells which can tolerate high concentrations of fungicidal agents. Persisters form upon attachment to a surface, an important step in the pathogenesis of Candida strains. The periodic application of antimicrobial agents may select for strains with increased levels of persister cells. In order to test this possibility, 150 isolates of Candida albicans and C. glabrata were obtained from cancer patients who were at high risk for the development of oral candidiasis and who had been treated with topical chlorhexidine once a day. Persister levels were measured by exposing biofilms growing in the wells of microtiter plates to high concentrations of amphotericin B and plating for survivors. The persister levels of the isolates varied from 0.2 to 9%, and strains isolated from patients with long-term carriage had high levels of persisters. High-persister strains were isolated from every patient with Candida carriage of more than 8 consecutive weeks but from no patients with transient carriage. All of the high-persister isolates had an amphotericin B MIC that was the same as that for the wild type, indicating that these strains were drug-tolerant rather than drug-resistant mutants. Biofilms of the majority of high-persister strains also showed an increased tolerance to chlorhexidine and had the same MIC for this antimicrobial as the wild type. This study suggests that persister cells are clinically relevant, and antimicrobial therapy selects for high-persister strains in vivo. The drug tolerance of persisters may be a critical but overlooked component responsible for antimicrobial drug failure and relapsing infections. PMID:19841146

Persistent Identifiers Implementation in EOSDIS

NASA Technical Reports Server (NTRS)

Ramapriyan, H. K. " Rama"

2016-01-01

This presentation provides the motivation for and status of implementation of persistent identifiers in NASA's Earth Observation System Data and Information System (EOSDIS). The motivation is provided from the point of view of long-term preservation of datasets such that a number of questions raised by current and future users can be answered easily and precisely. A number of artifacts need to be preserved along with datasets to make this possible, especially when the authors of datasets are no longer available to address users questions. The artifacts and datasets need to be uniquely and persistently identified and linked with each other for full traceability, understandability and scientific reproducibility. Current work in the Earth Science Data and Information System (ESDIS) Project and the Distributed Active Archive Centers (DAACs) in assigning Digital Object Identifiers (DOI) is discussed as well as challenges that remain to be addressed in the future.

Genomic characterization of a persistent rubella virus from a case of Fuch' uveitis syndrome in a 73 year old man.

PubMed

Abernathy, Emily; Peairs, Randall R; Chen, Min-hsin; Icenogle, Joseph; Namdari, Hassan

2015-08-01

Many cases of Fuchs' uveitis have been associated with persistent rubella virus infection. A 73-year-old male patient with typical Fuchs' Uveitis Syndrome (FUS) first experienced heterochromia of the left eye at the age fourteen, when rubella was endemic in the US. The purposes of this report are to describe the patient's FUS clinical presentations and to characterize the virus detected in the vitreous fluid. The patient underwent a therapeutic pars plana vitrectomy in May 2013. A real-time RT-PCR assay for rubella virus was performed on the vitreous fluid by Focus Diagnostics. Additional real-time RT-PCR assays for rubella virus detection and RT-PCR assays for generation of templates for sequencing were performed at the Centers for Disease Control and Prevention (CDC). The results from Focus Diagnostics were positive for rubella virus RNA. Real-time RT-PCR assays at CDC were also positive for rubella virus. A rubella virus sequence of 739 nucleotides was determined and phylogenetic analysis showed that the virus was the sole member of a new phylogenetic group when compared to reference virus sequences. While FUS remains a clinical diagnosis, findings in this case support the association between rubella virus and the disease. Phylogenetic analysis provided evidence that this rubella virus was likely a previously undetected genotype which is no longer circulating. Since the patient had rubella prior to 1955, this sequence is from the earliest rubella virus yet characterized. Copyright © 2015 Elsevier B.V. All rights reserved.

Persistence-Driven Durotaxis: Generic, Directed Motility in Rigidity Gradients

NASA Astrophysics Data System (ADS)

Novikova, Elizaveta A.; Raab, Matthew; Discher, Dennis E.; Storm, Cornelis

2017-02-01

Cells move differently on substrates with different rigidities: the persistence time of their motion is higher on stiffer substrates. We show that this behavior—in and of itself—results in a net flux of cells directed up a soft-to-stiff gradient. Using simple random walk models with varying persistence and stochastic simulations, we characterize the propensity to move in terms of the durotactic index also measured in experiments. A one-dimensional model captures the essential features and highlights the competition between diffusive spreading and linear, wavelike propagation. Persistence-driven durokinesis is generic and may be of use in the design of instructive environments for cells and other motile, mechanosensitive objects.

Electronic States and Persistent Currents in Nanowire Quantum Ring

NASA Astrophysics Data System (ADS)

Kokurin, I. A.

2018-04-01

The new model of a quantum ring (QR) defined inside a nanowire (NW) is proposed. The one-particle Hamiltonian for electron in [111]-oriented NW QR is constructed taking into account both Rashba and Dresselhaus spin-orbit coupling (SOC). The energy levels as a function of magnetic field are found using the exact numerical diagonalization. The persistent currents (both charge and spin) are calculated. The specificity of SOC and arising anticrossings in energy spectrum lead to unusual features in persistent current behavior. The variation of magnetic field or carrier concentration by means of gate can lead to pure spin persistent current with the charge current being zero.

Genetic evaluation of lactation persistency for five breeds of dairy cattle.

PubMed

Cole, J B; Null, D J

2009-05-01

Cows with high lactation persistency tend to produce less milk than expected at the beginning of lactation and more than expected at the end. Best prediction of lactation persistency is calculated as a function of trait-specific standard lactation curves and linear regressions of test-day deviations on days in milk. Because regression coefficients are deviations from a tipping point selected to make yield and lactation persistency phenotypically uncorrelated it should be possible to use 305-d actual yield and lactation persistency to predict yield for lactations with later endpoints. The objectives of this study were to calculate (co)variance components and breeding values for best predictions of lactation persistency of milk (PM), fat (PF), protein (PP), and somatic cell score (PSCS) in breeds other than Holstein, and to demonstrate the calculation of prediction equations for 400-d actual milk yield. Data included lactations from Ayrshire, Brown Swiss, Guernsey (GU), Jersey (JE), and Milking Shorthorn (MS) cows calving since 1997. The number of sires evaluated ranged from 86 (MS) to 3,192 (JE), and mean sire estimated breeding value for PM ranged from 0.001 (Ayrshire) to 0.10 (Brown Swiss); mean estimated breeding value for PSCS ranged from -0.01 (MS) to -0.043 (JE). Heritabilities were generally highest for PM (0.09 to 0.15) and lowest for PSCS (0.03 to 0.06), with PF and PP having intermediate values (0.07 to 0.13). Repeatabilities varied considerably between breeds, ranging from 0.08 (PSCS in GU, JE, and MS) to 0.28 (PM in GU). Genetic correlations of PM, PF, and PP with PSCS were moderate and favorable (negative), indicating that increasing lactation persistency of yield traits is associated with decreases in lactation persistency of SCS, as expected. Genetic correlations among yield and lactation persistency were low to moderate and ranged from -0.55 (PP in GU) to 0.40 (PP in MS). Prediction equations for 400-d milk yield were calculated for each breed by

Interaction between worsening renal function and persistent congestion in acute decompensated heart failure.

PubMed

Wattad, Malak; Darawsha, Wisam; Solomonica, Amir; Hijazi, Maher; Kaplan, Marielle; Makhoul, Badira F; Abassi, Zaid A; Azzam, Zaher S; Aronson, Doron

2015-04-01

Worsening renal function (WRF) and congestion are inextricably related pathophysiologically, suggesting that WRF occurring in conjunction with persistent congestion would be associated with worse clinical outcome. We studied the interdependence between WRF and persistent congestion in 762 patients with acute decompensated heart failure (HF). WRF was defined as ≥0.3 mg/dl increase in serum creatinine above baseline at any time during hospitalization and persistent congestion as ≥1 sign of congestion at discharge. The primary end point was all-cause mortality with mean follow-up of 15 ± 9 months. Readmission for HF was a secondary end point. Persistent congestion was more common in patients with WRF than in patients with stable renal function (51.0% vs 26.6%, p <0.0001). Both persistent congestion and persistent WRF were significantly associated with mortality (both p <0.0001). There was a strong interaction (p = 0.003) between persistent WRF and congestion, such that the increased risk for mortality occurred predominantly with both WRF and persistent congestion. The adjusted hazard ratio for mortality in patients with persistent congestion as compared with those without was 4.16 (95% confidence interval [CI] 2.20 to 7.86) in patients with WRF and 1.50 (95% CI 1.16 to 1.93) in patients without WRF. In conclusion, persisted congestion is frequently associated with WRF. We have identified a substantial interaction between persistent congestion and WRF such that congestion portends increased mortality particularly when associated with WRF. Copyright © 2015 Elsevier Inc. All rights reserved.

Evolutionary dynamics for persistent cooperation in structured populations

NASA Astrophysics Data System (ADS)

Li, Yan; Liu, Xinsheng; Claussen, Jens Christian; Guo, Wanlin

2015-06-01

The emergence and maintenance of cooperative behavior is a fascinating topic in evolutionary biology and social science. The public goods game (PGG) is a paradigm for exploring cooperative behavior. In PGG, the total resulting payoff is divided equally among all participants. This feature still leads to the dominance of defection without substantially magnifying the public good by a multiplying factor. Much effort has been made to explain the evolution of cooperative strategies, including a recent model in which only a portion of the total benefit is shared by all the players through introducing a new strategy named persistent cooperation. A persistent cooperator is a contributor who is willing to pay a second cost to retrieve the remaining portion of the payoff contributed by themselves. In a previous study, this model was analyzed in the framework of well-mixed populations. This paper focuses on discussing the persistent cooperation in lattice-structured populations. The evolutionary dynamics of the structured populations consisting of three types of competing players (pure cooperators, defectors, and persistent cooperators) are revealed by theoretical analysis and numerical simulations. In particular, the approximate expressions of fixation probabilities for strategies are derived on one-dimensional lattices. The phase diagrams of stationary states, and the evolution of frequencies and spatial patterns for strategies are illustrated on both one-dimensional and square lattices by simulations. Our results are consistent with the general observation that, at least in most situations, a structured population facilitates the evolution of cooperation. Specifically, here we find that the existence of persistent cooperators greatly suppresses the spreading of defectors under more relaxed conditions in structured populations compared to that obtained in well-mixed populations.

Trichomonas gallinae Persistence in Four Water Treatments.

PubMed

Purple, Kathryn E; Humm, Jacob M; Kirby, R Brian; Saidak, Christina G; Gerhold, Richard

2015-07-01

Trichomonas gallinae is a protozoan parasite commonly found in columbids, passerines, and several raptor species. Although T. gallinae is thought to spread between individuals and across species through shared water sources, little research has been conducted regarding the persistence of T. gallinae in the environment. To determine the persistence of T. gallinae in various communal water sources, we inoculated 1 × 10(6) trichomonads into 500 mL samples of distilled water, quarry water, bird bath water, and rain barrel water in two replicates. Aliquots of 0.5 mL were collected from each source at -1, 0, 15, 30, and 60 min; aliquots were incubated at 37 C and examined for trichomonads by light microscopy for five consecutive days. Live trichomonads were observed in all samples and at all sampling times except prior to inoculation (-1 min). The pH of water sources ranged from an average of 5.9 to 7.4 postsampling. Our findings indicate that T. gallinae can persist for up to 60 min in various water treatments and thus be infectious for birds drinking T. gallinae-contaminated water.

Overview of persistent pain in older adults.

PubMed

Molton, Ivan R; Terrill, Alexandra L

2014-01-01

With the shifting age demographics of the U.S. population, more psychologists will be asked to provide clinical services to older adults. Given the high prevalence of persistent pain in aging, in many cases this will mean providing empirically supported interventions for pain and the interference it creates. The purpose of this review is to provide a broad overview of the scope and impact of persistent pain in older people and to discuss mechanisms by which persistent geriatric pain can lead to suffering and disability. We consider the unique context of pain in older adulthood and review differences between older and younger people in terms of pain perception, the social network, beliefs about pain, pain-related coping, and adherence to pain medication. Finally, we discuss special issues affecting pain management in older adults, including dementia, polypharmacy, and barriers to accessing adequate pain care. This review also highlights a need for greater provider training in pain management to meet the needs of a changing U.S. population. PsycINFO Database Record (c) 2014 APA, all rights reserved.

The one-dimensional asymmetric persistent random walk

NASA Astrophysics Data System (ADS)

Rossetto, Vincent

2018-04-01

Persistent random walks are intermediate transport processes between a uniform rectilinear motion and a Brownian motion. They are formed by successive steps of random finite lengths and directions travelled at a fixed speed. The isotropic and symmetric 1D persistent random walk is governed by the telegrapher’s equation, also called the hyperbolic heat conduction equation. These equations have been designed to resolve the paradox of the infinite speed in the heat and diffusion equations. The finiteness of both the speed and the correlation length leads to several classes of random walks: Persistent random walk in one dimension can display anomalies that cannot arise for Brownian motion such as anisotropy and asymmetries. In this work we focus on the case where the mean free path is anisotropic, the only anomaly leading to a physics that is different from the telegrapher’s case. We derive exact expression of its Green’s function, for its scattering statistics and distribution of first-passage time at the origin. The phenomenology of the latter shows a transition for quantities like the escape probability and the residence time.

Academic Persistence and Black University Students' Perceived Personal Competencies.

ERIC Educational Resources Information Center

Steward, Robbie J.; Jackson, James

This study of the correlation between the self-concept of black university students and their academic persistence supports previous research identifying the importance of self-efficacy in academic persistence. Forty of the 115 18-year-old, American-born black freshmen, who lived on campus at a large predominantly white university, volunteered to…

College Student Persistence to Degree: The Burden of Debt

ERIC Educational Resources Information Center

Robb, Cliff A.; Moody, Beth; Abdel-Ghany, Mohamed

2012-01-01

Data collected from two major universities (one in the Midwest and one in the Southeast) in the United States were used to analyze student persistence behavior and perceptions of debt. Results from four separate logistic regression analyses suggested that financial factors play a significant role in student persistence behavior as well as in…

Trustworthy persistent identifier systems of the future

NASA Astrophysics Data System (ADS)

Golodoniuc, Pavel; Klump, Jens; Car, Nicholas

2016-04-01

Over the last two decades, persistent identifier (PID) systems have seen some significant changes in their governance policies, system capabilities, and technology. The development of most systems was driven by two main application areas, namely archives and libraries. Guidelines and criteria for trustworthy PID systems have been clearly devised (Bütikofer, 2009) and many PID system implementations for the identification of static digital objects have been built (e.g., PURL). However systems delivering persistent identifiers for dynamic datasets are not yet mature. There has been a rapid proliferation of different PID systems caused by the specific technical or organisational requirements of various communities that could not be met by existing systems such as DOI, ISBN, and EAN. Many of these different systems were limited by their inability to provide native means of persistent identifier resolution. This has prompted a decoupling of PID-associated data from the resolution service and this is where the Handle system has played a significant role. The Handle allowed to build a distributed system of independently managed resolver services. A trustworthy PID system must be designed to outlive the objects it provides persistent identifiers for, which may cease to exist or otherwise be deprecated, and the technology used to implement it, which will certainly need to change with time. We propose that such a system should rest on four pillars of agreements - (i) definitions, (ii) policies, (iii) services, and (iv) data services, to ensure longevity. While we believe all four pillars are equally important, we intentionally leave regulating aspects of issuing of identifiers and their registration out of the scope of this paper and focus on the agreements that have to be established between PID resolver services and the data sources indicated by the persistent identifiers. We propose an approach to development of PID systems that combines the use of (a) the Handle system

Towards a Better Understanding of Academic Persistence among Fresh-Men: A Qualitative Approach

ERIC Educational Resources Information Center

Roland, Nathalie; Frenay, Mariane; Boudrenghien, Gentiane

2016-01-01

Persistence in the first year at university is a phenomenon that has been studied many times. However, most research has taken a very linear view of the persistence process and little research has attempted to understand persistence by taking into account its full complexity. Yet the process of academic persistence is punctuated by striking events…

Saffold Virus Type 3 (SAFV-3) Persists in HeLa Cells

PubMed Central

Himeda, Toshiki; Hosomi, Takushi; Okuwa, Takako; Muraki, Yasushi; Ohara, Yoshiro

2013-01-01

Saffold virus (SAFV) was identified as a human cardiovirus in 2007. Although several epidemiological studies have been reported, they have failed to provide a clear picture of the relationship between SAFV and human diseases. SAFV genotype 3 has been isolated from the cerebrospinal fluid specimen of patient with aseptic meningitis. This finding is of interest since Theiler’s murine encephalomyelitis virus (TMEV), which is the closely related virus, is known to cause a multiple sclerosis-like syndrome in mice. TMEV persistently infects in mouse macrophage cells in vivo and in vitro, and the viral persistence is essential in TMEV-induced demyelinating disease. The precise mechanism(s) of SAFV infection still remain unclear. In order to clarify the SAFV pathogenicity, in the present study, we studied the possibilities of the in vitro persistent infection of SAFV. The two distinct phenotypes of HeLa cells, HeLa-N and HeLa-R, were identified. In these cells, the type of SAFV-3 infection was clearly different. HeLa-N cells were lyticly infected with SAFV-3 and the host suitable for the efficient growth. On the other hand, HeLa-R cells were persistently infected with SAFV-3. In addition, the SAFV persistence in HeLa-R cells is independent of type I IFN response of host cells although the TMEV persistence in mouse macrophage cells depends on the response. Furthermore, it was suggested that SAFV persistence may be influenced by the expression of receptor(s) for SAFV infection on the host cells. The present findings on SAFV persistence will provide the important information to encourage the research of SAFV pathogenicity. PMID:23308162

Relations between Preschool Attention Span-Persistence and Age 25 Educational Outcomes

PubMed Central

McClelland, Megan M.; Acock, Alan C.; Piccinin, Andrea; Rhea, Sally Ann; Stallings, Michael C.

2012-01-01

This study examined relations between children’s attention span-persistence in preschool and later school achievement and college completion. Children were drawn from the Colorado Adoption Project using adopted and non-adopted children (N = 430). Results of structural equation modeling indicated that children’s age 4 attention span-persistence significantly predicted math and reading achievement at age 21 after controlling for achievement levels at age 7, adopted status, child vocabulary skills, gender, and maternal education level. Relations between attention span-persistence and later achievement were not fully mediated by age 7 achievement levels. Logistic regressions also revealed that age 4 attention span-persistence skills significantly predicted the odds of completing college by age 25. The majority of this relationship was direct and was not significantly mediated by math or reading skills at age 7 or age 21. Specifically, children who were rated one standard deviation higher on attention span-persistence at age 4 had 48.7% greater odds of completing college by age 25. Discussion focuses on the importance of children’s early attention span-persistence for later school achievement and educational attainment. PMID:23543916

Early-Modern "Speech" Marks

ERIC Educational Resources Information Center

Blackburn, Nick

2011-01-01

This essay presents a revised history of the punctuation mark ["], drawn from the earliest communities who made it their own. By situating the development of ["] in its historical context, from first uses of the diple [diple] by the Greek scholar Aristarchus, it explains how it was the general applications which persisted into the sixteenth…

Factors of persistence among graduates of athletic training education programs.

PubMed

Bowman, Thomas G; Dodge, Thomas M

2011-01-01

Previous researchers have indicated that athletic training education programs (ATEPs) appear to retain students who are motivated and well integrated into their education programs. However, no researchers have examined the factors leading to successful persistence to graduation of recent graduates from ATEPs. To determine the factors that led students enrolled in a postprofessional education program accredited by the National Athletic Trainers' Association (NATA) to persist to graduation from accredited undergraduate ATEPs. Qualitative study. Postprofessional education program accredited by the NATA. Fourteen graduates (12 women, 2 men) of accredited undergraduate entry-level ATEPs who were enrolled in an NATA-accredited postprofessional education program volunteered to participate. We conducted semistructured interviews and analyzed data through a grounded theory approach. We used open, axial, and selective coding procedures. To ensure trustworthiness, 2 independent coders analyzed the data. The researchers then negotiated over the coding categories until they reached 100% agreement. We also performed member checks and peer debriefing. Four themes emerged from the data. Decisions to persist to graduation from ATEPs appeared to be influenced by students' positive interactions with faculty, clinical instructors, and peers. The environment of the ATEPs also affected their persistence. Participants thought they learned much in both the clinic and the classroom, and this learning motivated them to persist. Finally, participants could see themselves practicing athletic training as a career, and this greatly influenced their eventual persistence. Our study gives athletic training educators insight into the reasons students persist to graduation from ATEPs. Specifically, athletic training programs should strive to develop close-knit learning communities that stress positive interactions between students and instructors. Athletic training educators also must work to

Perceived Vocational Students' Intentional Persistence.

ERIC Educational Resources Information Center

Ikegulu, T. Nelson; Barham, Wilton A.; Farmer, Vernon L.; Roberson, Louvenia T.

A study investigated the distribution of attrition-related factors of 900 (351 male and 549 female) adult vocational students enrolled in selected postsecondary Louisiana vocational and technical institutions. Comparative, predictive, and ex-post facto designs were used. The outcome measure was students' perceived intentional persistence, which…

Persistent anxiety and in-hospital complications after acute coronary syndrome

PubMed Central

AbuRuz, Mohannad Eid

2018-01-01

Objectives: To investigate the effects of pre-event persistent anxiety on in-hospital complications and length of stay (LOS) in patients who experienced acute coronary syndrome (ACS). Methods: This was a prospective study with patients seeking treatment for ACS events. Anxiety was measured 2 times before the event in 600 patients with pre-existing coronary heart disease (CHD). Patients were followed for 2 years or until they developed an ACS event. 120 patients developed ACS events (rate 20%). Complications and LOS were abstracted from medical records. Results: Persistently non-anxious patients have lower anxiety scores at 3 months follow-up than baseline (mean [standard deviation (SD)], 6.1 [0.24] vs. 3.9 [0.95], P <0.01). Patients with persistent anxiety had significantly higher complication rates than non-anxious patients (mean [SD], 0.71 [0.12] vs. 0.15 [0.11], P <0.05). In a multiple logistic regression, persistent anxiety was an independent predictor of complications. Patients who were persistently anxious were at 5 times higher risk for developing complications (odds ratio = 5.0, 95% confidence interval: 1.27–38.8, P < 0.05). Conclusion: Anxiety measured up to 2 years before an ACS event was predictive of in-hospital complications. Clinicians caring for patients with CHD need to be as equally aware of the importance of assessing and treating persistent anxiety as clinicians caring for patients hospitalized for an ACS. PMID:29599695

Brain differences between persistent and remitted attention deficit hyperactivity disorder.

PubMed

Mattfeld, Aaron T; Gabrieli, John D E; Biederman, Joseph; Spencer, Thomas; Brown, Ariel; Kotte, Amelia; Kagan, Elana; Whitfield-Gabrieli, Susan

2014-09-01

Previous resting state studies examining the brain basis of attention deficit hyperactivity disorder have not distinguished between patients who persist versus those who remit from the diagnosis as adults. To characterize the neurobiological differences and similarities of persistence and remittance, we performed resting state functional magnetic resonance imaging in individuals who had been longitudinally and uniformly characterized as having or not having attention deficit hyperactivity disorder in childhood and again in adulthood (16 years after baseline assessment). Intrinsic functional brain organization was measured in patients who had a persistent diagnosis in childhood and adulthood (n = 13), in patients who met diagnosis in childhood but not in adulthood (n = 22), and in control participants who never had attention deficit hyperactivity disorder (n = 17). A positive functional correlation between posterior cingulate and medial prefrontal cortices, major components of the default-mode network, was reduced only in patients whose diagnosis persisted into adulthood. A negative functional correlation between medial and dorsolateral prefrontal cortices was reduced in both persistent and remitted patients. The neurobiological dissociation between the persistence and remittance of attention deficit hyperactivity disorder may provide a framework for the relation between the clinical diagnosis, which indicates the need for treatment, and additional deficits that are common, such as executive dysfunctions. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Frequency of bacetrial content finding in persistant periapical lesions

PubMed Central

Grgurević, Joško; Tambić Andrašević, Arjana; Prpić Mehičić, Goranka; Kuzmac, Sania; Jukić, Silvana

2017-01-01

Objectives To determine the percentage of persistant apical lesions positive for bacterial nucleic acids, to detect microorganisms difficult to cultivate in persistant apical lesions by PCR and relate them to endodontic failure, clinical symptoms and diabetes mellitus. Materials and methods The samples of persistent apical lesions were collected during apicoectomy. Bacterial ubiquitous primer 16S rRNA was used to detect 16S ribosomal RNA in 36 samples. A species–specific PCR was performed with primers targeted to the bacterial 16S rRNA genes of Prevotella Nigrescens, Pseudoramibacter alactolyticus, and Propionobacterium propionicum. Results Six samples (16.67%) were positive for bacterial ribosomal RNA. Pseudoramibacter alactolyticus was detected in three samples. Propionibacterium propionicum and Prevotella nigrescens were detected in one sample each. The prevalence of infection of such lesions with P. intermedia, P. propionicum and P. alactolyticus is low. Conslusion The study we conducted gave insufficient data about extraradicular infection and its connection with diabetes mellitus and clinical symptoms. Conclusions Apical lesions persisting after endodontic treatment could harbor microorganisms other than Actinomyces and Propionicum species. PMID:29225362

Cranial Bosses of Choerosaurus dejageri (Therapsida, Therocephalia): Earliest Evidence of Cranial Display Structures in Eutheriodonts

PubMed Central

Benoit, Julien; Manger, Paul R.; Fernandez, Vincent; Rubidge, Bruce S.

2016-01-01

Choerosaurus dejageri, a non-mammalian eutheriodont therapsid from the South African late Permian (~259 Ma), has conspicuous hemispheric cranial bosses on the maxilla and the mandible. These bosses, the earliest of this nature in a eutheriodont, potentially make C. dejageri a key species for understanding the evolutionary origins of sexually selective behaviours (intraspecific competition, ritualized sexual and intimidation displays) associated with cranial outgrowths at the root of the clade that eventually led to extant mammals. Comparison with the tapinocephalid dinocephalian Moschops capensis, a therapsid in which head butting is strongly supported, shows that the delicate structure of the cranial bosses and the gracile structure of the skull of Choerosaurus would be more suitable for display and low energy combat than vigorous head butting. Thus, despite the fact that Choerosaurus is represented by only one skull (which makes it impossible to address the question of sexual dimorphism), its cranial bosses are better interpreted as structures involved in intraspecific selection, i.e. low-energy fighting or display. Display structures, such as enlarged canines and cranial bosses, are widespread among basal therapsid clades and are also present in the putative basal therapsid Tetraceratops insignis. This suggests that sexual selection may have played a more important role in the distant origin and evolution of mammals earlier than previously thought. Sexual selection may explain the subsequent independent evolution of cranial outgrowths and pachyostosis in different therapsid lineages (Biarmosuchia, Dinocephalia, Gorgonopsia and Dicynodontia). PMID:27548428

Cranial Bosses of Choerosaurus dejageri (Therapsida, Therocephalia): Earliest Evidence of Cranial Display Structures in Eutheriodonts.

PubMed

Benoit, Julien; Manger, Paul R; Fernandez, Vincent; Rubidge, Bruce S

2016-01-01

Choerosaurus dejageri, a non-mammalian eutheriodont therapsid from the South African late Permian (~259 Ma), has conspicuous hemispheric cranial bosses on the maxilla and the mandible. These bosses, the earliest of this nature in a eutheriodont, potentially make C. dejageri a key species for understanding the evolutionary origins of sexually selective behaviours (intraspecific competition, ritualized sexual and intimidation displays) associated with cranial outgrowths at the root of the clade that eventually led to extant mammals. Comparison with the tapinocephalid dinocephalian Moschops capensis, a therapsid in which head butting is strongly supported, shows that the delicate structure of the cranial bosses and the gracile structure of the skull of Choerosaurus would be more suitable for display and low energy combat than vigorous head butting. Thus, despite the fact that Choerosaurus is represented by only one skull (which makes it impossible to address the question of sexual dimorphism), its cranial bosses are better interpreted as structures involved in intraspecific selection, i.e. low-energy fighting or display. Display structures, such as enlarged canines and cranial bosses, are widespread among basal therapsid clades and are also present in the putative basal therapsid Tetraceratops insignis. This suggests that sexual selection may have played a more important role in the distant origin and evolution of mammals earlier than previously thought. Sexual selection may explain the subsequent independent evolution of cranial outgrowths and pachyostosis in different therapsid lineages (Biarmosuchia, Dinocephalia, Gorgonopsia and Dicynodontia).

Multigene phylogeny of land plants with special reference to bryophytes and the earliest land plants.

PubMed

Nickrent, D L; Parkinson, C L; Palmer, J D; Duff, R J

2000-12-01

A widely held view of land plant relationships places liverworts as the first branch of the land plant tree, whereas some molecular analyses and a cladistic study of morphological characters indicate that hornworts are the earliest land plants. To help resolve this conflict, we used parsimony and likelihood methods to analyze a 6, 095-character data set composed of four genes (chloroplast rbcL and small-subunit rDNA from all three plant genomes) from all major land plant lineages. In all analyses, significant support was obtained for the monophyly of vascular plants, lycophytes, ferns (including PSILOTUM: and EQUISETUM:), seed plants, and angiosperms. Relationships among the three bryophyte lineages were unresolved in parsimony analyses in which all positions were included and weighted equally. However, in parsimony and likelihood analyses in which rbcL third-codon-position transitions were either excluded or downweighted (due to apparent saturation), hornworts were placed as sister to all other land plants, with mosses and liverworts jointly forming the second deepest lineage. Decay analyses and Kishino-Hasegawa tests of the third-position-excluded data set showed significant support for the hornwort-basal topology over several alternative topologies, including the commonly cited liverwort-basal topology. Among the four genes used, mitochondrial small-subunit rDNA showed the lowest homoplasy and alone recovered essentially the same topology as the multigene tree. This molecular phylogeny presents new opportunities to assess paleontological evidence and morphological innovations that occurred during the early evolution of terrestrial plants.

School Working Conditions and Changes in Student Teachers' Planned Persistence in Teaching

ERIC Educational Resources Information Center

Shirrell, Matthew; Reininger, Michelle

2017-01-01

This study examines the relationship between the working conditions of student teaching schools and changes in student teachers' planned persistence in teaching. Planned persistence (and a related construct, initial commitment) is an important predictor of initial entry (Rots, Aelterman, Vlerick, & Vermeulen, 2007) and actual persistence in…

Avian persistence in fragmented rainforest.

PubMed

Lens, Luc; Van Dongen, Stefan; Norris, Ken; Githiru, Mwangi; Matthysen, Erik

2002-11-08

What factors determine the persistence of species in fragmented habitats? To address this question, we studied the relative impacts of forest deterioration and fragmentation on bird species in 12 rainforest fragments in Kenya, combining 6 years of individual capture-recapture data with measurements of current captures and museum specimens. Species mobility, as estimated from species-specific dispersal rates, and tolerance to habitat deterioration, as estimated from change in fluctuating asymmetry with increasing habitat disturbance, explained 88% of the variation in patch occupancy among eight forest bird species. Occupancy increased with mobility and with tolerance to deterioration, where both variables contributed equally to this relationship. We conclude that individual-level study, such as of dispersal behavior and phenotypic development, can predict patterns of persistence at the species level. More generally, for conservation tactics to stand a high chance of success, they should include action both within sites, to minimize habitat deterioration, and across landscapes, to maximize dispersal.

Persistent Pemphigus Vulgaris Showing Features of Tufted Hair Folliculitis

PubMed Central

Ko, Dong Kyun; Chae, In Soo; Chung, Ki Hun; Chung, Hyun

2011-01-01

Pemphigus vulgaris is an autoimmune blistering disease that commonly involves the scalp. Lesions of pemphigus vulgaris that persist on the scalp for a long period may be accompanied by tufted hair folliculitis. Only two previous accounts of tufted hair folliculitis developing in a lesion of pemphigus vulgaris have been reported. We report a 51-year-old-man with erosions and clusters of hair on the scalp. The scalp lesion had persisted for about 20 years. A histopathological examination of the skin lesion on the scalp revealed separation of the epidermis and clusters of several adjacent hair follicles. The patient was diagnosed with persistent pemphigus vulgaris of the scalp showing features of tufted hair folliculitis. PMID:22148026

The oldest known primate skeleton and early haplorhine evolution.

PubMed

Ni, Xijun; Gebo, Daniel L; Dagosto, Marian; Meng, Jin; Tafforeau, Paul; Flynn, John J; Beard, K Christopher

2013-06-06

Reconstructing the earliest phases of primate evolution has been impeded by gaps in the fossil record, so that disagreements persist regarding the palaeobiology and phylogenetic relationships of the earliest primates. Here we report the discovery of a nearly complete and partly articulated skeleton of a primitive haplorhine primate from the early Eocene of China, about 55 million years ago, the oldest fossil primate of this quality ever recovered. Coupled with detailed morphological examination using propagation phase contrast X-ray synchrotron microtomography, our phylogenetic analysis based on total available evidence indicates that this fossil is the most basal known member of the tarsiiform clade. In addition to providing further support for an early dichotomy between the strepsirrhine and haplorhine clades, this new primate further constrains the age of divergence between tarsiiforms and anthropoids. It also strengthens the hypothesis that the earliest primates were probably diurnal, arboreal and primarily insectivorous mammals the size of modern pygmy mouse lemurs.

Persistent hyperthyroidism and de novo Graves' ophthalmopathy after total thyroidectomy.

PubMed

Tay, Wei Lin; Loh, Wann Jia; Lee, Lianne Ai Ling; Chng, Chiaw Ling

2017-01-01

We report a patient with Graves' disease who remained persistently hyperthyroid after a total thyroidectomy and also developed de novo Graves' ophthalmopathy 5 months after surgery. She was subsequently found to have a mature cystic teratoma containing struma ovarii after undergoing a total hysterectomy and salpingo-oophorectomy for an incidental ovarian lesion. It is important to investigate for other causes of primary hyperthyroidism when thyrotoxicosis persists after total thyroidectomy.TSH receptor antibody may persist after total thyroidectomy and may potentially contribute to the development of de novo Graves' ophthalmopathy.

Creepy White Gaze: Rethinking the Diorama as a Pedagogical Activity

ERIC Educational Resources Information Center

Sterzuk, Andrea; Mulholland, Valerie

2011-01-01

Drawing on gaze and postcolonial theory, this article provides a theoretical discussion of a problematic photograph published in a provincial teachers' newsletter. The photo consists of a White settler child and two White settler educators gathered around his heritage fair entry diorama entitled "Great Plains Indians." This article…

Role of Prefrontal Persistent Activity in Working Memory

PubMed Central

Riley, Mitchell R.; Constantinidis, Christos

2016-01-01

The prefrontal cortex is activated during working memory, as evidenced by fMRI results in human studies and neurophysiological recordings in animal models. Persistent activity during the delay period of working memory tasks, after the offset of stimuli that subjects are required to remember, has traditionally been thought of as the neural correlate of working memory. In the last few years several findings have cast doubt on the role of this activity. By some accounts, activity in other brain areas, such as the primary visual and posterior parietal cortex, is a better predictor of information maintained in visual working memory and working memory performance; dynamic patterns of activity may convey information without requiring persistent activity at all; and prefrontal neurons may be ill-suited to represent non-spatial information about the features and identity of remembered stimuli. Alternative interpretations about the role of the prefrontal cortex have thus been suggested, such as that it provides a top-down control of information represented in other brain areas, rather than maintaining a working memory trace itself. Here we review evidence for and against the role of prefrontal persistent activity, with a focus on visual neurophysiology. We show that persistent activity predicts behavioral parameters precisely in working memory tasks. We illustrate that prefrontal cortex represents features of stimuli other than their spatial location, and that this information is largely absent from early cortical areas during working memory. We examine memory models not dependent on persistent activity, and conclude that each of those models could mediate only a limited range of memory-dependent behaviors. We review activity decoded from brain areas other than the prefrontal cortex during working memory and demonstrate that these areas alone cannot mediate working memory maintenance, particularly in the presence of distractors. We finally discuss the discrepancy between

The persistence and character of stranded oil on coarse-sediment beaches.

PubMed

Owens, Edward H; Taylor, Elliott; Humphrey, Blair

2008-01-01

Small amounts of oil that can persist for decades in the intertidal zone of coarse-sediment beaches have been documented in a few well-studied cases. Oil that survives attenuation over the short-term (weeks to months) will persist until there is a change in the environmental conditions, as might occur where there is a seasonal storm-wave climate or as a beach undergoes long-term (erosional) changes. Oil residues can persist on the beach surface as tar mats, asphalt-like pavements, or as veneers on sediment particles or hard surfaces. Subsurface oil residues can persist in similar forms or as fill or partial fill of the pore spaces between coarse-sediment particles. Oil penetrates until it reaches fine-grained sediment, the water table, bedrock, or other penetration-limiting layers. Amounts of persistent oil are very small fractions of the volumes that were originally stranded and these protected residues can continue to biodegrade as they become thinner and more discontinuous.

Considerations of persistence and security in CHOICES, an object-oriented operating system

NASA Technical Reports Server (NTRS)

Campbell, Roy H.; Madany, Peter W.

1990-01-01

The current design of the CHOICES persistent object implementation is summarized, and research in progress is outlined. CHOICES is implemented as an object-oriented system, and persistent objects appear to simplify and unify many functions of the system. It is demonstrated that persistent data can be accessed through an object-oriented file system model as efficiently as by an existing optimized commercial file system. The object-oriented file system can be specialized to provide an object store for persistent objects. The problems that arise in building an efficient persistent object scheme in a 32-bit virtual address space that only uses paging are described. Despite its limitations, the solution presented allows quite large numbers of objects to be active simultaneously, and permits sharing and efficient method calls.

The earliest drawings of datable auroras and a two-tail comet from the Syriac Chronicle of Zūqnīn

NASA Astrophysics Data System (ADS)

Hayakawa, Hisashi; Mitsuma, Yasuyuki; Fujiwara, Yasunori; Kawamura, Akito Davis; Kataoka, Ryuho; Ebihara, Yusuke; Kosaka, Shunsuke; Iwahashi, Kiyomi; Tamazawa, Harufumi; Isobe, Hiroaki

2017-04-01

People have probably been watching the sky since the beginning of human history. Observers in pre-telescopic ages recorded anomalous events, which now provide uniquely valuable information for modern scientists. Records that include drawings are particularly useful, since the verbal expressions recorded by pre-telescopic observers, who did not know the physical nature of the phenomena, are often ambiguous. However, drawings concerning specific datable events in the historical documents are far fewer than the verbal records. Therefore, in this paper we show the possible earliest drawings of datable auroras and a two-tail comet included in a manuscript of the Chronicle of Zūqnīn, a Syriac chronicle up to 775/776 CE, to interpret their nature. Careful perusing the original Syriac autograph manuscript, MS Vat.Sir.162, provide not only historical facts in the realm around Amida, but also information concerning low-latitude aurora observations due to extreme space weather events and the existence of sun-grazing comets.

Postepizootic Persistence of Venezuelan Equine Encephalitis Virus, Venezuela

PubMed Central

Navarro, Juan-Carlos; Medina, Gladys; Vasquez, Clovis; Coffey, Lark L.; Wang, Eryu; Suárez, Alexander; Biord, Hernán; Salas, Marlene

2005-01-01

Five years after the apparent end of the major 1995 Venezuelan equine encephalitis (VEE) epizootic/epidemic, focal outbreaks of equine encephalitis occurred in Carabobo and Barinas States of western Venezuela. Virus isolates from horses in each location were nearly identical in sequence to 1995 isolates, which suggests natural persistence of subtype IC VEE virus (VEEV) strains in a genetically stable mode. Serologic evidence indicated that additional outbreaks occurred in Barinas State in 2003. Field studies identified known Culex (Melanoconion) spp. vectors and reservoir hosts of enzootic VEEV but a dearth of typical epidemic vectors. Cattle serosurveys indicated the recent circulation of enzootic VEEV strains, and possibly of epizootic strains. Persistence of VEEV subtype IC strains and infection of horses at the end of the rainy season suggest the possibility of an alternative, cryptic transmission cycle involving survival through the dry season of infected vectors or persistently infected vertebrates. PMID:16485478

Marine predators and persistent prey in the southeast Bering Sea

NASA Astrophysics Data System (ADS)

Sigler, Michael F.; Kuletz, Kathy J.; Ressler, Patrick H.; Friday, Nancy A.; Wilson, Christopher D.; Zerbini, Alexandre N.

2012-06-01

Predictable prey locations reduce search time and energetic costs of foraging; thus marine predators often exploit locations where prey concentrations persist. In our study, we examined whether this association is influenced by differences among predator species in foraging modes (travel cost, surface feeder or diver) or whether the predator species is a central place forager or not. We examined distributions of two seabird species during their nesting period, the surface-feeding black-legged kittiwake (Rissa tridactyla) and the pursuit-diving thick-billed murre (Uria lomvia), and two baleen whale species, the humpback whale (Megaptera novaeangliae) and the fin whale (Balaenoptera physalus), in relation to two key prey, age-1 walleye pollock (Theragra chalcogramma) and euphausiids (Euphausiidae). Prey surveys were conducted once each year during 2004 and 2006-2010. Concurrent predator surveys were conducted in 2006-2010 (seabirds) and 2008 and 2010 (whales). We compared the seabird and whale foraging locations to where age-1 pollock and euphausiids were concentrated and considered the persistence of these concentrations, where the time-scale of persistence is year (i.e., a comparison among surveys that are conducted once each year). Euphausiids were widespread and concentrations often were reliably found within specific 37 km×37 km blocks ('persistent hot spots of prey'). In contrast, age-1 pollock were more concentrated and their hot spots were persistent only on coarser scales (>37 km). Both seabird species, regardless of foraging mode, were associated with age-1 pollock but not with euphausiids, even though age-1 pollock were less persistent than euphausiids. The higher travel cost central place foragers, thick-billed murres, foraged at prey concentrations nearer their island colonies than black-legged kittiwakes, which were more widespread foragers. Humpback whales were not tied to a central place and mostly were located only where euphausiids were

Transcriptomic study on persistence and survival of Listeria monocytogenes following lethal treatment with Nisin.

PubMed

Wu, Shuyan; Yu, Pak-Lam; Wheeler, Dave; Flint, Steve

2018-06-19

The aim of this study was to determine the gene expression associated with the persistence of a Listeria monocytogenes stationary phase population when facing lethal nisin treatment METHODS: RNA Seq analysis was used for gene expression profiling of the persister cells in rich medium (persister TN) compared with untreated cells (non-persister).The results were confirmed using RT PCR. Functional genes associated with the persister populations were identified in multiple systems, such as heat shock related stress response, cell wall synthesis, ATP-binding cassette (ABC) transport system, phosphotransferase system (PTS system), and SOS/DNA repair. This study pointed to genetic regulation of persister cells exposed to lethal nisin and provides some insight into possible mechanisms of impeding bacterial persistence. Copyright © 2018. Published by Elsevier Ltd.

On the Parity of Structural Persistence in Language Production and Comprehension

PubMed Central

Tooley, Kristen M.; Bock, Kathryn

2014-01-01

Structural priming creates structural persistence. That is, differences in experience with syntax can change subsequent language performance, and the changes can be observed in both language production and comprehension. However, the effects in comprehension and production appear to differ. In comprehension, persistence is typically found when the verbs are the same in primes and targets; in production, persistence occurs without verb overlap. The contrast suggests a theoretically important hypothesis: parsing in comprehension is lexically driven while formulation in production is structurally driven. A major weakness in this hypothesis about comprehension-production differences is that its empirical motivation rests on the outcomes of experiments in which the priming manipulations differ, the primed sentence structures differ, and the measures of priming differ. To sharpen the comparison, we examined structural persistence with and without verb overlap in both reading comprehension and spoken production, using the same prime presentation procedure, the same syntactic structures, the same sentences, and the same participants. These methods yielded abstract sructural persistence in comprehension as well as production. A measure of the strength of persistence revealed significant effects of priming and verb overlap without significant comprehension—production differences. This argues for uniformity in the structural mechanisms of language processing. PMID:24803423

A TOXICITY IDENTIFICATION EVALUATION OF SILTY MARINE HARBOR SEDIMENTS TO CHARACTERIZE PERSISTENT AND NON-PERSISTENT CONSTITUENTS

EPA Science Inventory

Sediment toxicity in silty marine harbor sediments is frequently dominated by ammonia or sulfide, leaving the adverse effects of persistent toxic substances unnoticed. To investigate the latter, we subjected interstitial water from three contaminated silty sediments to toxicity i...

Earliest date for milk use in the Near East and southeastern Europe linked to cattle herding.

PubMed

Evershed, Richard P; Payne, Sebastian; Sherratt, Andrew G; Copley, Mark S; Coolidge, Jennifer; Urem-Kotsu, Duska; Kotsakis, Kostas; Ozdoğan, Mehmet; Ozdoğan, Aslý E; Nieuwenhuyse, Olivier; Akkermans, Peter M M G; Bailey, Douglass; Andeescu, Radian-Romus; Campbell, Stuart; Farid, Shahina; Hodder, Ian; Yalman, Nurcan; Ozbaşaran, Mihriban; Biçakci, Erhan; Garfinkel, Yossef; Levy, Thomas; Burton, Margie M

2008-09-25

The domestication of cattle, sheep and goats had already taken place in the Near East by the eighth millennium bc. Although there would have been considerable economic and nutritional gains from using these animals for their milk and other products from living animals-that is, traction and wool-the first clear evidence for these appears much later, from the late fifth and fourth millennia bc. Hence, the timing and region in which milking was first practised remain unknown. Organic residues preserved in archaeological pottery have provided direct evidence for the use of milk in the fourth millennium in Britain, and in the sixth millennium in eastern Europe, based on the delta(13)C values of the major fatty acids of milk fat. Here we apply this approach to more than 2,200 pottery vessels from sites in the Near East and southeastern Europe dating from the fifth to the seventh millennia bc. We show that milk was in use by the seventh millennium; this is the earliest direct evidence to date. Milking was particularly important in northwestern Anatolia, pointing to regional differences linked with conditions more favourable to cattle compared to other regions, where sheep and goats were relatively common and milk use less important. The latter is supported by correlations between the fat type and animal bone evidence.

Association of Inhaled Corticosteroids and Long-Acting Muscarinic Antagonists With Asthma Control in Patients With Uncontrolled, Persistent Asthma: A Systematic Review and Meta-analysis.

PubMed

Sobieraj, Diana M; Baker, William L; Nguyen, Elaine; Weeda, Erin R; Coleman, Craig I; White, C Michael; Lazarus, Stephen C; Blake, Kathryn V; Lang, Jason E

2018-04-10

Long-acting muscarinic antagonists (LAMAs) are a potential adjunct therapy to inhaled corticosteroids in the management of persistent asthma. To conduct a systematic review and meta-analysis of the effects associated with LAMA vs placebo or vs other controllers as an add-on therapy to inhaled corticosteroids and the use of a LAMA as add-on therapy to inhaled corticosteroids and long-acting β-agonists (LABAs; hereafter referred to as triple therapy) vs inhaled corticosteroids and LABA in patients with uncontrolled, persistent asthma. MEDLINE, EMBASE, Cochrane databases, and clinical trial registries (earliest date through November 28, 2017). Two reviewers selected randomized clinical trials or observational studies evaluating a LAMA vs placebo or vs another controller as an add-on therapy to inhaled corticosteroids or triple therapy vs inhaled corticosteroids and LABA in patients with uncontrolled, persistent asthma reporting on an outcome of interest. Meta-analyses using a random-effects model was conducted to calculate risk ratios (RRs), risk differences (RDs), and mean differences (MDs) with corresponding 95% CIs. Citation screening, data abstraction, risk assessment, and strength-of-evidence grading were completed by 2 independent reviewers. Asthma exacerbations. Of 1326 records identified, 15 randomized clinical trials (N = 7122 patients) were included. Most trials assessed adding LAMA vs placebo or LAMA vs LABA to inhaled corticosteroids. Adding LAMA vs placebo to inhaled corticosteroids was associated with a significantly reduced risk of exacerbation requiring systemic corticosteroids (RR, 0.67 [95% CI, 0.48 to 0.92]; RD, -0.02 [95% CI, -0.04 to 0.00]). Compared with adding LABA, adding LAMA to inhaled corticosteroids was not associated with significant improvements in exacerbation risk (RR, 0.87 [95% CI, 0.53 to 1.42]; RD, 0.00 [95% CI, -0.02 to 0.02]), or any other outcomes of interest. Triple therapy was not significantly associated with improved

First-Year Persistence and Retention. Snapshot™ Report, Spring 2017

ERIC Educational Resources Information Center

National Student Clearinghouse, 2017

2017-01-01

Of all students who started college in fall 2015, 73.4 percent persisted at any U.S. institution in fall 2016, while 61.1 percent were retained at their starting institution. The persistence rate is the percentage of students who return to college at any institution for their second year, while the retention rate is the percentage of students who…

Low prevalence of lactase persistence in Neolithic South-West Europe

PubMed Central

Plantinga, Theo S; Alonso, Santos; Izagirre, Neskuts; Hervella, Montserrat; Fregel, Rosa; van der Meer, Jos WM; Netea, Mihai G; de la Rúa, Concepcion

2012-01-01

The ability of humans to digest the milk component lactose after weaning requires persistent production of the lactose-converting enzyme lactase. Genetic variation in the promoter of the lactase gene (LCT) is known to be associated with lactase production and is therefore a genetic determinant for either lactase deficiency or lactase persistence during adulthood. Large differences in this genetic trait exist between populations in Africa and the Middle-East on the one hand, and European populations on the other; this is thought to be due to evolutionary pressures exerted by consumption of dairy products in Neolithic populations in Europe. In this study, we have investigated lactase persistence of 26 out of 46 individuals from Late Neolithic through analysis of ancient South-West European DNA samples, obtained from two burials in the Basque Country originating from 5000 to 4500 YBP. This investigation revealed that these populations had an average frequency of lactase persistence of 27%, much lower than in the modern Basque population, which is compatible with the concept that Neolithic and post-Neolithic evolutionary pressures by cattle domestication and consumption of dairy products led to high lactase persistence in Southern European populations. Given the heterogeneity in the frequency of the lactase persistence allele in ancient Europe, we suggest that in Southern Europe the selective advantage of lactose assimilation in adulthood most likely took place from standing population variation, after cattle domestication, at a post-Neolithic time when fresh milk consumption was already fully adopted as a consequence of a cultural influence. PMID:22234158

The transfer of diatoms from freshwater to footwear materials: An experimental study assessing transfer, persistence, and extraction methods for forensic reconstruction.

PubMed

Levin, E A; Morgan, R M; Scott, K R; Jones, V J

2017-09-01

In recent years there has been growing interest in environmental forms of trace evidence, and ecological trace evidence collected from footwear has proved valuable within casework. Simultaneously, there has been growing awareness of the need for empirical experimentation to underpin forensic inferences. Diatoms are unicellular algae, and each cell (or 'frustule') consists of two valves which are made of silica, a robust material that favours their preservation both in sediments and within forensic scenarios. A series of experiments were carried out to investigate the transfer and persistence of diatoms upon common footwear materials, a recipient surface that has historically been overlooked by studies of persistence. The effectiveness of two novel extraction techniques (jet rinsing, and heating and agitation with distilled water) was compared to the established extraction technique of hydrogen peroxide digestion, for a suite of five common footwear materials: canvas, leather, and 'suede' (representing upper materials), and rubber and polyurethane (representing sole materials). It was observed that the novel extraction technique of heating and agitation with distilled water did not extract fewer diatom valves, or cause increased fragmentation of valves, when compared to peroxide digestion, suggesting that the method may be viable where potentially hazardous chemical reactions may be encountered with the peroxide digestion method. Valves could be extracted from all five footwear materials after 3min of immersion, and more valves were extracted from the rougher, woven upper materials than the smoother sole materials. Canvas yielded the most valves (a mean of 2511/cm 2 ) and polyurethane the fewest (a mean of 15/cm 2 ). The persistence of diatoms on the three upper materials was addressed with a preliminary pilot investigation, with ten intervals sampled between 0 and 168h. Valves were seen to persist in detectable quantities after 168h on all three upper materials

The Hispano Ranchos of Northern New Mexico: Continuity and Change. Teaching with Historic Places.

ERIC Educational Resources Information Center

Koman, Rita G.

Northern New Mexico boasts river valleys surrounded by snow covered mountains. But it is also harsh and unforgiving. One settler called it a "glorious hell." The "Hispanos," as the early Spanish settlers and their descendants were called, and the "Anglos," the immigrants from the east, were often in conflict. The…

A Life in the Sun: Accounts of New Lives Abroad as Intercultural Narratives

ERIC Educational Resources Information Center

Beaven, Tita

2007-01-01

Through an analysis of three settler narratives about new lives in Spain, Stewart (1999), Kerr (2000) and Lambert (2000), the paper explores three elements of these intercultural narratives that contribute to the formation of the settler's new sociocultural identity: the physical environment, explorations of the other through signs of the…

Pregnancy persistently affects memory T cell populations.

PubMed

Kieffer, Tom E C; Faas, Marijke M; Scherjon, Sicco A; Prins, Jelmer R

2017-02-01

Pregnancy is an immune challenge to the maternal immune system. The effects of pregnancy on maternal immunity and particularly on memory T cells during and after pregnancy are not fully known. This observational study aims to show the short term and the long term effects of pregnancy on the constitution, size and activation status of peripheral human memory T-lymphocyte populations. Effector memory (EM) and central memory (CM) T-lymphocytes were analyzed using flow cytometry of peripheral blood from 14 nulligravid, 12 primigravid and 15 parous women that were on average 18 months postpartum. The short term effects were shown by the significantly higher CD4+ EM cell and activated CD4+ memory cell proportions in primigravid women compared to nulligravid women. The persistent effects found in this study were the significantly higher proportions of CD4+ EM, CD4+ CM and activated memory T cells in parous women compared to nulligravid women. In contrast to CD4+ cells, activation status of CD8+ memory cells did not differ between the groups. This study shows that pregnancy persistently affects the pre-pregnancy CD4+ memory cell pool in human peripheral blood. During pregnancy, CD4+ T-lymphocytes might differentiate into EM cells followed by persistent higher proportions of CD4+ CM and EM cells postpartum. The persistent effects of pregnancy on memory T cells found in this study support the hypothesis that memory T cells are generated during pregnancy and that these cells could be involved in the lower complication risks in multiparous pregnancies in humans. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Persistence of Agrobacterium tumefaciens in transformed conifers.

PubMed

Charity, Julia A; Klimaszewska, Krystyna

2005-01-01

Previous studies have shown that the widely used plant transformation vector Agrobacterium tumefaciens can persist in genetically engineered plants in vitro and in transgenic greenhouse-grown plants, despite the use of counter-selective antibiotics. However, little is known regarding Agrobacterium persistence in tree species. To understand the kinetics of A. tumefaciens decline and persistence in transformation experiments, we assayed for the presence of A. tumefaciens in spruce and pine embryogenic tissue for up to 10 weeks post-transformation. The A. tumefaciens populations declined rapidly in the first five days post-cocultivation but generally declined more slowly in pine, relative to spruce. No bacteria were detected in spruce embryogenic tissue beyond four weeks after cocultivation, however in pine there were -100 colony forming units per g tissue at 10 weeks post-cocultivation. We present evidence that the detection limit for PCR using virD2 primers to detect A. tumefaciens in a background of pine needle DNA was approximately 10(9)-10(10) A. tumefaciens cells per g of tissue. We also assayed for A. tumefaciens in transgenic pine and spruce embryogenic tissue and from needles, branches, stems and roots of transformed plants, up to four years post-inoculation. Occasionally A. tumefaciens was detected in embryogenic tissue up to 12 months post-inoculation. A. tumefaciens was never detected in cultured embryogenic tissue more than twelve months after inoculation, nor in developing somatic embryos or germinating plantlets, nor any of the parts of greenhouse-grown plants. From these data we conclude that if A. tumefaciens persists in transgenic conifers, it does so beneath our ability to detect it.