bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous determination of dihydroxybenzene positional isomers by capillary electrochromatography using gold nanoparticles as stationary phase
Authors: He Jian‐Feng , Yao Fu‐Jun , Cui Hong , Li Xiang‐Jun , Yuan Zhuo‐Bin
Published: May 2012

The paper describes the enhanced separation of o‐, m‐, p‐dihydroxybenzene by capillary electrochromatography (CEC) using gold nanoparticles (AuNPs) as stationary phase. The effect of the AuNPs concentration upon separation was investigated. The experimental parameters, including separation voltage, pH, and concentration of running buffer, were optimized. Under the optimum conditions, a good resolution of three dihydroxybenzene isomers was obtained within 15 min in a 50 cm effective length capillary modified with 0.02 nmol/L AuNPs at a separation voltage of 16 kV in a 50 mmol/L acetate buffer (pH 5.0). The linear ranges were from 10−6 to 10−4 mol/L and the detection limits were as low as 10−7 mol/L. This method was successfully used to analysis two kinds of hair coloring agent sample with recoveries in the range of 90–105% and relative standard deviations (RSD) less than 5.0%.
Open‐tubular capillary electrochromatography with bare gold nanoparticles‐based stationary phase applied to separation of trypsin digested native and glycated proteins
Authors: Mikšík Ivan , Lacinová Kateřina , Zmatlíková Zdeňka , Sedláková Pavla , Král Vladimír , Sýkora David , Řezanka Pavel , Kašička Václav
Published: May 2012

In this work, open‐tubular capillary electrochromatography (OT‐CEC) method with bare gold nanoparticles (GNPs)‐based stationary phase has been developed and applied for separation of tryptic peptide fragments of native and glycated proteins, bovine serum albumin (BSA), and human transferrin (HTF). The GNPs‐based stationary phase was prepared by immobilization of bare GNPs, freshly reduced from tetrachloroaurate(III) ions by citrate reduction, on the sol‐gel pretreated inner wall of the fused silica capillary. The separation efficiency, peak capacity, and peptide recovery of this open‐tubular capillary column were investigated by varying the experimental parameters such as type and concentration of the buffering constituent and pH of the background electrolyte (BGE), temperature, and separation voltage. The best separations of the above tryptic peptides were achieved in the BGE composed of aqueous 100 mmol/L sodium phosphate buffer, pH 2.5, at separation voltage 10 kV per 47‐cm long, 50 μm inside diameter capillary thermostated at 25°C. OT‐CEC with bare GNPs stationary phase is shown to be a suitable technique for separation of complex peptide mixtures arising from tryptic digestion of native and glycated BSA and HTF, and for investigation of glycation (nonenzymatic glycosylation) of these proteins.
Sidestream microstream end tidal carbon dioxide measurements and blood gas correlations in neonatal intensive care unit
Authors: Singh Bindya S. , Gilbert Urquidez , Singh Sharad , Govindaswami Balaji
Published: May 2012

Objective

The study was designed to assess the use of newer sidestream microstream end tidal carbon dioxide (ETCO2) device in predicting blood carbon dioxide (PCO2) measurements in very low birth weight (VLBW = birth weight <1,500 g) and non‐VLBW NICU neonates.

Study Design

Sidestream microstream ETCO2 detectors were allowed time to calibrate and reach steady state prior to blood gas measurements. Blood CO2 (PCO2) and simultaneous ETCO2 were recorded. Ratio of dead space to tidal volume (VD/VT) was calculated using modified Bohr's equation. Correlation coefficient, estimates of difference, standard deviation, and 95% limits of agreement between ETCO2 and PCO2 concentrations were calculated.

Results

Two hundred eighty‐six paired samples were collected from 48 ventilated NICU patients. Average PCO2 and ETCO2 were 58.4 and 50.6 with a correlation of 0.76. Subgroup analysis showed a correlation of 0.73 in 204 paired blood from 34 VLBW infants and 0.82 in 82 paired samples from non‐VLBW infants. Estimates of difference ± standard deviation between PCO2 and ETCO2 concentrations in these three groups, respectively (ALL, VLBW, and non‐VLBW) were 7.84 ± 9.96, 8.2 ± 10.16, and 6.95 ± 9.45. The correlation coefficient significantly improved in the VLBW group to 0.86 with dead space to tidal volume ratio (VD/VT) <30% (0.86 vs. 0.42; P < 0.001).

Conclusion

ETCO2 measurements using sidestream microstream technology in VLBW demonstrated that the correlation of ETCO2 and PCO2 was moderate, but the agreement was less than adequate (bias > 5 mmHg in all groups). The results improved with lower VD/VT, suggesting that sidestream capnography is more reliable in conditions of less severe lung disease. Pediatr Pulmonol. 2013; 48:250–256. © 2012 Wiley Periodicals, Inc.
Wind turbine load reduction by rejecting the periodic load disturbances
Authors: Houtzager I. , van Wingerden J.W. , Verhaegen M.
Published: May 2012

For the cost per kilowatt hour to be decreased, the trend in offshore wind turbines is to increase the rotor diameter as much as possible. The increasing dimensions have led to a relative increase of the loads on the wind turbine structure; thus, it is necessary to react to disturbances in a more detailed way, e.g. each blade separately. The disturbances acting on an individual wind turbine blade are to a large extent deterministic; for instance, tower shadow, wind shear, yawed error and gravity are depending on the rotational speed and azimuth angle and will change slowly over time. This paper aims to contribute to the development of individually pitch‐controlled blades by proposing a lifted repetitive controller that can reject these periodic load disturbances for modern fixed‐speed wind turbines and modern variable‐speed wind turbines operating above‐rated. The performance of the repetitive control method is evaluated on the UPWIND 5 MW wind turbine model and compared with typical individual pitch control. Simulation results indicate that for relatively slow changing periodic wind disturbances, this lifted repetitive control method can significantly reduce the vibrations in the wind turbine structure with considerably less high‐frequent control action. Copyright © 2012 John Wiley & Sons, Ltd.
Parametric X‐ray radiation as a novel source for X‐ray imaging
Authors: Takahashi Yumiko , Hayakawa Yasushi , Kuwada Takao , Tanaka Toshinari , Sakae Toshiro , Nakao Keisuke , Nogami Kyoko , Imagaki Manabu , Hayakawa Ken , Sato Isamu
Published: May 2012

A novel X‐ray source based on parametric X‐ray radiation (PXR) has been put into practical use at the Laboratory for Electron Beam Research and Application (LEBRA), Nihon University, Japan. The PXR beam has been generated from a Si single crystal irradiated by a 100‐MeV electron beam from a linac at the LEBRA. In this study, phase‐contrast imaging experiments using a diffraction‐enhanced imaging (DEI) method have been carried out by using the parametric X‐rays at an energy of 17.5 keV. The successful images obtained by the DEI method have shown detailed inner structures of soft biological tissues more clearly as compared with those by conventional absorption radiography. Given the significant properties of the LEBRA PXR source, i.e., compact system, large X‐ray beam irradiation field of approximately 80 mm in diameter and quasi‐monochromaticity, the result suggests a possible construction of a compact linac‐driven PXR‐DEI device and application to medical diagnoses. Copyright © 2012 John Wiley & Sons, Ltd.
Shaping black holes with free fields
Authors: Bardoux Yannis , Caldarelli Marco M. , Charmousis Christos
Published: May 2012

Abstract

Starting from a metric Ansatz permitting a weak version of Birkhoff’s theorem we find static black hole solutions including matter in the form of free scalar and p-form fields, with and without a cosmological constant Λ. Single p-form matter fields permit multiple possibilities, including dyonic solutions, self-dual instantons and metrics with Einstein-Kälher horizons. The inclusion of multiple p-forms on the other hand, arranged in a homogeneous fashion with respect to the horizon geometry, permits the construction of higher dimensional dyonic p-form black holes and four dimensional axionic black holes with flat horizons, when Λ < 0. It is found that axionic fields regularize black hole solutions in the sense, for example, of permitting regular — rather than singular — small mass Reissner-Nordstrom type black holes. Their cosmic string and Vaidya versions are also obtained.
Trauma Care and Case Fatality during a Period of Frequent, Violent Terror Attacks and Thereafter
Authors: Rivkind Avraham I. , Blum Rony , Gershenstein Irena , Stein Yael , Coleman Shula , Mintz Yoav , Zamir Gideon , Richter Elihu D.
Published: May 2012

Background

From September 1999 through January 2004 during the second Intifada (al‐Aqsa), there were frequent terror attacks in Jerusalem. We assessed the effects on case fatality of introducing a specialized, intensified approach to trauma care at the Hebrew University‐Hadassah Hospital Shock Trauma Unit (HHSTU) and other level I Israeli trauma units. This approach included close senior supervision of prehospital triage, transport, and all surgical procedures and longer hospital stays despite high patient‐staff ratios and low hospital budgets. Care for lower income patients also was subsidized.

Methods

We tracked case fatality rates (CFRs) initially during a period of terror attacks (1999–2003) in 8,127 patients (190 deaths) at HHSTU in subgroups categorized by age, injury circumstances, and injury severity scores (ISSs). Our comparisons were four other Israeli level I trauma centers (n = 2,000 patients), and 51 level I U.S. trauma centers (n = 265,902 patients; 15,237 deaths). Detailed HHSTU follow‐up continued to 2010.

Results

Five‐year HHSTU CFR (2.62 %) was less than half that in 51 U.S. centers (5.73 %). CFR progressively decreased; in contrast to a rising trend in the US for all age groups, injury types, and ISS groupings, including gunshot wounds (GSW). Patients with ISS > 25 accounted for 170 (89 %) of the 190 deaths in HHSTU. Forty‐one lives were saved notionally based on U.S. CFRs within this group. However, far more lives were saved from reductions in low CFRs in large numbers of patients with ISS < 25. CFRs in HHSTU and other Israeli trauma units decreased more through the decade to 1.9 % up to 2010.

Conclusions

Sustained reductions in trauma unit CFRs followed introduction of a specialized, intensified approach to trauma care.
Raummuster unterschiedlicher Wissensformen. Der Einfluss von Transaktionskosten auf Konzentrationsprozesse wissensintensiver Dienstleister im deutschen Städtesystem
Authors: Growe Anna , Growe Anna
Published: May 2012

The increasing importance of knowledge as factor in economic processes leads to a reappraisal of economic locations. In this paper spatial consequences of this reappraisal are discussed using the example of the German urban system. Key functions in processes of knowledge production and knowledge use are knowledge-based services. Their locations as well as changes of their locations are of major interest from a geographic perspective. As theory supports assumptions about concentration processes as well as assumptions about processes of de-concentration, empirical evidence is crucial in this context. In this paper it is asked whether the use of different forms of knowledge leads to different spatial patterns of knowledge-based services, depending on the height of transaction costs. It is assumed that the more location specific and the harder to codify the used knowledge form, the more concentrated knowledge-based services that use the respective knowledge form will be.
Pathways Into Youth Justice: Strengthening Policy and Program Supports for Young People in the Youth Justice System Who Are Transitioning From Out-of-Home Care
Authors: Mendes Philip , Baidawi Susan
Published: May 2012

Local and international research suggests an overrepresentation of young people leaving state out-of-home care in the youth justice system. A range of factors appear to contribute to this correlation including child abuse and neglect, placement instability, experiences of residential care, and unsupported transitions from care. This article presents the findings of a Victorian pilot study conducted in partnership with Whitelion, a not-for-profit organisation specifically offering support to ‘young people involved with or at risk of involvement with the youth justice and/or out-of-home care and leaving care services’ (Whitelion, 2012), to examine the interrelationship between the child protection and youth justice systems, and particularly to explore the processes that take place when young people involved in the youth justice system leave state care. A series of interviews and focus groups with Whitelion workers were used to explore whether leaving care plans and policies address and minimise involvement with youth justice; the role, if any, of formal consultations by child protection services with youth justice regarding this group of care leavers; and the ongoing role of youth justice postcare, particularly when young people are in custody at the time of their exit from care. Some significant implications for policy and practice are identified.
Out-of-Home Care As an Institutional Risk Environment for Volatile Substance Use
Authors: MacLean Sarah
Published: May 2012

The exploratory study of meanings of volatile substance use (VSU) on which this article draws (involving 28 young people living in Melbourne, Victoria, Australa, aged from 13 to 24 years, each with experience of VSU, and 14 expert workers) was not designed to investigate any relationship between VSU and living in out-of-home care while subject to protective orders. However, when asked about their lives at the time they commenced or intensified VSU, 8 participants were adamant that living in out-of-home care was a significant factor. Two narratives reiterated by these young people are identified in the article: first that VSU is part of life in out-of-home care, and second that VSU ceases to be appropriate after leaving care. Young people who are living in out-of-home care report substantially higher levels of VSU than occur across the general population. This article shows how narrative accounts (even when expressed by small numbers of participants) provide insight into how VSU and other drug use may become embedded in particular institutional settings through assuming meanings and utility for users that are specific to these environments. While previous literature on the aetiology of VSU generally emphasises individual or familial risk factors, this article argues that out-of-home care may function, at least in some instances, as an institutional ‘risk environment’ for VSU and that this should be further explored through future research. Adjusting models of care may offer new strategies for responding to this form of drug use.
It Is Not Just Music and Rhythm . . . Evaluation of a Drumming-Based Intervention to Improve the Social Wellbeing of Alienated Youth
Authors: Faulkner Simon , Wood Lisa , Ivery Penny , Donovan Robert
Published: May 2012

The Discovering Relationship Using Music, Beliefs, Emotions, Attitudes & Thoughts (DRUMBEAT) program used drumming as a way of engaging at risk youth in a form of musical expression, while simultaneously incorporating themes and discussions relating to healthy relationships with others. The program targeted young people who are alienated from the school system. An evaluation was undertaken with a sample of 60 program participants in Western Australia's Wheatbelt region. The evaluation used both quantitative and qualitative methods, including informal discussions with staff and participants, observation, participant and teacher questionnaires, and school attendance and behavioural incident records. Pre- and postintervention data were collected on self-esteem, school attendance, antisocial behaviour, and levels of cooperation and collaboration. Students participating in DRUMBEAT increased their scores over a range of social indicators that act to increase connection with the school community. The results support the underlying program theory, that combining the therapeutic potential of musical expression with basic cognitive–behavioural therapy can be used successfully to deliver a range of social learning outcomes, including emotional control, improved relationships and increased self-esteem. Further longitudinal studies are required to assess the sustainability of the measured outcomes and their vulnerability to external factors.
ON CONTINUOUS SOLUTIONS OF AN EQUATION OF THE GOŁA̧B–SCHINZEL TYPE
Authors: JABŁOŃSKA ELIZA
Published: May 2012

We characterise solutions f,g:ℝ→ℝ of the functional equation f(x+g(x)y)=f(x)f(y) under the assumption that f is continuous. Our considerations refer mainly to a paper by Chudziak [‘Semigroup-valued solutions of the Goła̧b–Schinzel functional equation’, Abh. Math. Semin. Univ. Hambg. 76, (2006), 91–98], in which the author studied the same equation assuming that g is continuous.
“They don't just disappear”: Acknowledging death in the long-term care setting
Authors: Maitland Janine , Brazil Kevin , James-Abra Bill
Published: May 2012

Objective:

The purpose of this study was to describe the value of a formal room blessing ritual held within a long-term care facility, from the perspectives of staff, residents, and family members.

Method:

A qualitative research study involving interviews with staff, residents, and family members was conducted to examine the perceived value of a room blessing ritual.

Results:

Twenty-four room blessing attendees participated in the study (nine staff, eight residents, and seven family members). Attendees felt that the room blessing provided an opportunity to formally acknowledge the death of the resident and their grief; the majority felt that this was a positive experience and that it provided an element of closure. Staff members and residents expressed their appreciation for the opportunity to connect with family members of the deceased to express their condolences during the ritual. Participants also identified the inclusivity of the ritual (i.e., an open invitation to all staff, residents, and family members) as a positive aspect that served as a reminder that others shared in their grief. Staff members felt that blessing the room for the new resident was an important component of the ritual, helping to bridge the gap between mourning and welcoming a new person. Staff, residents, and family members felt that the room blessing positively reflected the mission and values of the facility. The most highly valued aspect of the ritual for all attendees was the sharing of stories about the deceased to celebrate that person's life.

Significance of results:

Long-term care facilities need to recognize that formal supports to manage the bereavement needs of staff and residents, such as a room blessing ritual, should be incorporated into their model for managing end-of-life care, given the relationship between the emotional health of staff and the quality of care provided for residents.
Interaction between cognition and emotion in developmental psychopathology: the role of linguistic stimuli
Authors: Bellani M. , Bonivento C. , Brambilla P.
Published: May 2012

Investigations on emotional words demonstrated that processing emotional information in child patients with anxiety disorders diagnosed for anxiety (generalized anxiety disorder and post-traumatic stress disorder) or depression is biased towards pathology-related stimuli. Also, neuroimaging studies showed a failure of prefrontal areas in inhibiting the emotional reaction in children with bipolar disorder. Finally, despite several studies investigated memory and attention using emotional words, little is known about the development of emotional lexicon in both healthy and psychopathological children.
Characteristics of spacecraft charging in low Earth orbit
Authors: Anderson Phillip C.
Published: May 2012

It has been found that the DMSP spacecraft at 840 km can charge to very large negative voltages (up to −2000 V) when encountering intense precipitating electron events (auroral arcs). We present an 11‐year study of over 1600 charging events, defined as when the spacecraft charged to levels exceeding 100 V negative during an auroral crossing. The occurrence frequency of events was highly correlated with the 11‐year solar cycle with the largest number of events occurring during solar minimum. This was due to the requirement that the background thermal plasma density be low, at most 104 cm−3. During solar maximum, the plasma density is typically well above that level due to the solar EUV ionizing radiation, and although the occurrence frequency of auroral arcs is considerably greater than at solar minimum, the occurrence of high‐level charging is minimal. As a result of this study, we produced a model spectrum for precipitating electrons that can be used as a specification for the low‐altitude auroral charging environment. There are implications from this study on a number of LEO satellite programs, including the International Space Station, which does enter the auroral zone, particularly during geomagnetic activity when the auroral boundary can penetrate to very low latitudes. The plasma density in the ISS orbit is usually well above the minimum required density for charging. However, in the wake of the ISS, the plasma density can be 2 orders of magnitude or more lower than the background density and thus conditions are ripe for charging.
The master transit time distribution of variable flow systems
Authors: Heidbüchel Ingo , Troch Peter A. , Lyon Steve W. , Weiler Markus
Published: May 2012

The transit time of water is an important indicator of catchment functioning and affects many biological and geochemical processes. Water entering a catchment at one point in time is composed of water molecules that will spend different amounts of time in the catchment before exiting. The next water input pulse can exhibit a totally different distribution of transit times. The distribution of water transit times is thus best characterized by a time‐variable probability density function. It is often assumed, however, that the variability of the transit time distribution is negligible and that catchments can be characterized with a unique transit time distribution. In many cases this assumption is not valid because of variations in precipitation, evapotranspiration, and catchment water storage and associated (de)activation of dominant flow paths. This paper presents a general method to estimate the time‐variable transit time distribution of catchment waters. Application of the method using several years of rainfall‐runoff and stable water isotope data yields an ensemble of transit time distributions with different moments. The combined probability density function represents the master transit time distribution and characterizes the intra‐annual and interannual variability of catchment storage and flow paths. Comparing the derived master transit time distributions of two research catchments (one humid and one semiarid) reveals differences in dominant hydrologic processes and dynamic water storage behavior, with the semiarid catchment generally reacting slower to precipitation events and containing a lower fraction of preevent water in the immediate hydrologic response.
Effect of wave frequency and directional spread on shoreline runup
Authors: Guza R. T. , Feddersen Falk
Published: May 2012

Wave breaking across the surf zone elevates the mean water level at the shoreline (setup), and drives fluctuations about the mean (runup). Runup often is divided into sea‐swell (0.04–0.3 Hz) and lower frequency infragravity (0.00–0.04 Hz) components. With energetic incident waves, runup is dominated by infragravity frequencies, and total water levels (combined setup and runup) can exceed 3 m, significantly contributing to coastal flooding and erosion. Setup and runup observations on sandy beaches are scattered about empirical parameterizations based on near‐shoreline beach slope and deep water wave height and wavelength. Accurate parameterizations are needed to determine flooding and erosion risk to coastal ecosystems and communities. Here, numerical simulations with the Boussinesq wave model funwaveC are shown to statistically reproduce typical empirical setup and runup parameterizations. Furthermore, the model infragravity runupRs(ig) strongly depends on the incident wave directional and frequency spread (about the mean direction and peak frequency). Realistic directional spread variations change Rs(ig) equivalent to a factor of two variation in incident wave height. The modeled Rs(ig)is shown to vary systematically with a new, non‐dimensional spreading parameter that involves peak frequency, frequency spread, and directional spread. This suggests a new parameterization forRs(ig) potentially useful to predict coastal flooding and erosion.
Thermal characterization of GaN-based laser diodes by forward-voltage method
Authors: Feng M. X. , Zhang S. M. , Jiang D. S. , Liu J. P. , Wang H. , Zeng C. , Li Z. C. , Wang H. B. , Wang F. , Yang H.
Published: May 2012

An expression of the relation between junction temperature and forward voltage common for both GaN-based laser diodes (LDs) and light emitting diodes is derived. By the expression, the junction temperature of GaN-based LDs emitting at 405 nm was measured at different injection current and compared with the result of micro-Raman spectroscopy, showing that the expression is reasonable. In addition, the activation energy of Mg in AlGaN/GaN superlattice layers is obtained based on the temperature dependence of forward voltage.
Theoretical study of Si-based ionic switch
Authors: Yamauchi Takashi , Young Yang Moon , Kamiya Katsumasa , Shiraishi Kenji , Nakayama Takashi
Published: May 2012

We studied the formation/dissolution of a silver (Ag) filament in a silicon (Si) layer through the first-principles calculations. We found these processes take place reversibly by switching the polarity of the bias voltage, bringing about the large resistance change of the Si layer. Furthermore, we developed a model to describe the current-voltage (I-V) characteristics for the Ag(electrode)/Si(electrolyte)/p-Si(electrode) switch device and analyzed the experimental result [S. H. Jo and W. Lu, Nano Lett. 8, 392 (2008)] in the case of using an amorphous Si(a-Si) layer as the electrolyte. It was suggested from the simulated results that dendritic Ag filaments with a fractal dimension of 1.6 are formed in the a-Si layer.
Liver-stage malaria parasites vulnerable to diverse chemical scaffolds
Authors: Derbyshire Emily R. , Prudêncio Miguel , Mota Maria M. , Clardy Jon
Published: May 2012

Human malaria infection begins with a one-time asymptomatic liver stage followed by a cyclic symptomatic blood stage. All high-throughput malaria drug discovery efforts have focused on the cyclic blood stage, which has limited potential for the prophylaxis, transmission blocking, and eradication efforts that will be needed in the future. To address these unmet needs, a high-throughput phenotypic liver-stage
Plasmodium
parasite screen was developed to systematically identify molecules with liver-stage efficacy. The screen recapitulates liver-stage infection by isolating luciferase-expressing
Plasmodium berghei
parasites directly from the salivary glands of infected mosquitoes, adding them to confluent human liver cells in 384-well plates, and measuring luciferase activity after a suitable incubation period. Screening 5,375 known bioactive compounds identified 37 liver-stage malaria inhibitors with diverse modes of action, as shown by inhibition time course experiments. Further analysis of the hits in the Food and Drug Administration-approved drug subset revealed compounds that seem to act specifically on the liver stage of infection, suggesting that this phase of the parasite’s life cycle presents a promising area for new drug discovery. Notably, many active compounds in this screen have molecular structures and putative targets distinctly different from those of known antimalarial agents.
Y-chromosome analysis reveals genetic divergence and new founding native lineages in Athapaskan- and Eskimoan-speaking populations
Authors: Dulik Matthew C. , Owings Amanda C. , Gaieski Jill B. , Vilar Miguel G. , Andre Alestine , Lennie Crystal , Mackenzie Mary Adele , Kritsch Ingrid , Snowshoe Sharon , Wright Ruth , Martin James , Gibson Nancy , Andrews Thomas D. , Schurr Theodore G. ,   The Genographic Consortium,   The Genographic Consortium., Adhikarla Syama , Adler Christina J. , Balanovska Elena , Balanovsky Oleg , Bertranpetit Jaume , Clarke Andrew C. , Comas David , Cooper Alan , Der Sarkissian Clio S. I. , GaneshPrasad ArunKumar , Haak Wolfgang , Haber Marc , Hobbs Angela , Javed Asif , Jin Li , Kaplan Matthew E. , Li Shilin , Martínez-Cruz Begoña , Matisoo-Smith Elizabeth A. , Melé Marta , Merchant Nirav C. , Mitchell R. John , Parida Laxmi , Pitchappan Ramasamy , Platt Daniel E. , Quintana-Murci Lluis , Renfrew Colin , Lacerda Daniela R. , Royyuru Ajay K. , Santos Fabrício R. , Soodyall Himla , Soria Hernanz David F. , Swamikrishnan Pandikumar , Tyler-Smith Chris , Santhakumari Arun Varatharajan , Vieira Pedro Paulo , Wells R. Spencer , Zalloua Pierre A. , Ziegle Janet S.
Published: May 2012

For decades, the peopling of the Americas has been explored through the analysis of uniparentally inherited genetic systems in Native American populations and the comparison of these genetic data with current linguistic groupings. In northern North America, two language families predominate: Eskimo-Aleut and Na-Dene. Although the genetic evidence from nuclear and mtDNA loci suggest that speakers of these language families share a distinct biological origin, this model has not been examined using data from paternally inherited Y chromosomes. To test this hypothesis and elucidate the migration histories of Eskimoan- and Athapaskan-speaking populations, we analyzed Y-chromosomal data from Inuvialuit, Gwich’in, and Tłįchǫ populations living in the Northwest Territories of Canada. Over 100 biallelic markers and 19 chromosome short tandem repeats (STRs) were genotyped to produce a high-resolution dataset of Y chromosomes from these groups. Among these markers is an SNP discovered in the Inuvialuit that differentiates them from other Aboriginal and Native American populations. The data suggest that Canadian Eskimoan- and Athapaskan-speaking populations are genetically distinct from one another and that the formation of these groups was the result of two population expansions that occurred after the initial movement of people into the Americas. In addition, the population history of Athapaskan speakers is complex, with the Tłįchǫ being distinct from other Athapaskan groups. The high-resolution biallelic data also make clear that Y-chromosomal diversity among the first Native Americans was greater than previously recognized.
Superpenetration optical microscopy by iterative multiphoton adaptive compensation technique
Authors: Tang Jianyong , Germain Ronald N. , Cui Meng
Published: May 2012

Biological tissues are rarely transparent, presenting major challenges for deep tissue optical microscopy. The achievable imaging depth is fundamentally limited by wavefront distortions caused by aberration and random scattering. Here, we report an iterative wavefront compensation technique that takes advantage of the nonlinearity of multiphoton signals to determine and compensate for these distortions and to focus light inside deep tissues. Different from conventional adaptive optics methods, this technique can rapidly measure highly complicated wavefront distortions encountered in deep tissue imaging and provide compensations for not only aberration but random scattering. The technique is tested with a variety of highly heterogeneous biological samples including mouse brain tissue, skull, and lymph nodes. We show that high quality three-dimensional imaging can be realized at depths beyond the reach of conventional multiphoton microscopy and adaptive optics methods, albeit over restricted distances for a given correction. Moreover, the required laser excitation power can be greatly reduced in deep tissues, deviating from the power requirement of ballistic light excitation and thus significantly reducing photo damage to the biological tissue.
Context and dating of Aurignacian vulvar representations from Abri Castanet, France
Authors: White Randall , Mensan Romain , Bourrillon Raphaëlle , Cretin Catherine , Higham Thomas F. G. , Clark Amy E. , Sisk Matthew L. , Tartar Elise , Gardère Philippe , Goldberg Paul , Pelegrin Jacques , Valladas Hélène , Tisnérat-Laborde Nadine , de Sanoit Jacques , Chambellan Dominique , Chiotti Laurent
Published: May 2012

We report here on the 2007 discovery, in perfect archaeological context, of part of the engraved and ocre-stained undersurface of the collapsed rockshelter ceiling from Abri Castanet, Dordogne, France. The decorated surface of the 1.5-t roof-collapse block was in direct contact with the exposed archaeological surface onto which it fell. Because there was no sedimentation between the engraved surface and the archaeological layer upon which it collapsed, it is clear that the Early Aurignacian occupants of the shelter were the authors of the ceiling imagery. This discovery contributes an important dimension to our understanding of the earliest graphic representation in southwestern France, almost all of which was discovered before modern methods of archaeological excavation and analysis. Comparison of the dates for the Castanet ceiling and those directly obtained from the Chauvet paintings reveal that the “vulvar” representations from southwestern France are as old or older than the very different wall images from Chauvet.
Pupil dilation deconvolution reveals the dynamics of attention at high temporal resolution
Authors: Wierda Stefan M. , van Rijn Hedderik , Taatgen Niels A. , Martens Sander
Published: May 2012

The size of the human pupil increases as a function of mental effort. However, this response is slow, and therefore its use is thought to be limited to measurements of slow tasks or tasks in which meaningful events are temporally well separated. Here we show that high-temporal-resolution tracking of attention and cognitive processes can be obtained from the slow pupillary response. Using automated dilation deconvolution, we isolated and tracked the dynamics of attention in a fast-paced temporal attention task, allowing us to uncover the amount of mental activity that is critical for conscious perception of relevant stimuli. We thus found evidence for specific temporal expectancy effects in attention that have eluded detection using neuroimaging methods such as EEG. Combining this approach with other neuroimaging techniques can open many research opportunities to study the temporal dynamics of the mind’s inner eye in great detail.
Isolation of phosphatidylethanolamine as a solitary cofactor for prion formation in the absence of nucleic acids
Authors: Deleault Nathan R. , Piro Justin R. , Walsh Daniel J. , Wang Fei , Ma Jiyan , Geoghegan James C. , Supattapone Surachai
Published: May 2012

Infectious prions containing the pathogenic conformer of the mammalian prion protein (PrP
Sc
) can be produced de novo from a mixture of the normal conformer (PrP
C
) with RNA and lipid molecules. Recent reconstitution studies indicate that nucleic acids are not required for the propagation of mouse prions in vitro, suggesting the existence of an alternative prion propagation cofactor in brain tissue. However, the identity and functional properties of this unique cofactor are unknown. Here, we show by purification and reconstitution that the molecule responsible for the nuclease-resistant cofactor activity in brain is endogenous phosphatidylethanolamine (PE). Synthetic PE alone facilitates conversion of purified recombinant (rec)PrP substrate into infectious recPrP
Sc
molecules. Other phospholipids, including phosphatidylcholine, phosphatidylserine, phosphatidylinositol, and phosphatidylglycerol, were unable to facilitate recPrP
Sc
formation in the absence of RNA. PE facilitated the propagation of PrP
Sc
molecules derived from all four different animal species tested including mouse, suggesting that unlike RNA, PE is a promiscuous cofactor for PrP
Sc
formation in vitro. Phospholipase treatment abolished the ability of brain homogenate to reconstitute the propagation of both mouse and hamster PrP
Sc
molecules. Our results identify a single endogenous cofactor able to facilitate the formation of prions from multiple species in the absence of nucleic acids or other polyanions.
An analytical scattering function for polydisperse spherical core–shell particles with Schulz–Flory size distributions of both core size and shell thickness
Authors: Wagner Joachim
Published: May 2012

The scattering function for polydisperse core–shell particles with Schulz–Flory size distributions of both the core radius and the shell thickness is analytically calculated. The results of the analytical solution are compared with the results of a numerical integration over both size distributions, as well as with available analytical solutions for homogeneous spheres. The CPU time required for the calculation of the scattering function can be reduced by several orders of magnitude compared with numerical integration. This is of tremendous importance in nonlinear curve fitting requiring repeated calculation of the theoretical function in an iterative process.
Na7Mg13Nd(PO4)12
Authors: Jerbi Hasna , Hidouri Mourad , Mongi Ben Amara
Published: May 2012

Investigations of the quasi-ternary system Na3PO4–Mg3(PO4)2–NdPO4 allowed us to obtain the new phosphate heptasodium tridecamagnesium neodymium dodecakisphosphate, Na7Mg13Nd(PO4)12, by applying a flux method. The crystal structure is isotypic with that of the previously reported Na7Mg13
Ln(PO4)12 (Ln = Eu, La) compounds. It consists of a complex three-dimensional framework built up from an NdO8 polyhedron (m symmetry), an MO6 octahedron statistically occupied by M = Mg and Na, and eight MgO
x
(x = 5, 6) polyhedra (four with site symmetry m), linked either directely by sharing corners, edges and faces, or by one of the eight unique PO4 tetrahedra through common corners. Two of the PO4 tetrahedra are statisticaly disordered over a mirror plane. The whole structure can be described as resutling from an assembly of two types of structural units, viz [Mg4
MP4O22]∞
2 layers extending parallel to (100) and stacked along [100], and [Mg4NdP4O36]∞
1 undulating chains running along the [010] direction. The six different Na+ cations (five with site symmetry m and one with 0.5 occupancy) are situated in six distinct cavities delimited by the framework. The structure was refined from data of a racemic twin.
1-(5-Bromo-4-phenyl-1,3-thiazol-2-yl)pyrrolidin-2-one
Authors: Ghabbour Hazem A. , Kadi Adnan A. , El-Subbagh Hussein I. , Chia Tze Shyang , Fun Hoong-Kun
Published: May 2012

The asymmetric unit of the title compound, C13H11BrN2OS, consists of two crystallographically independent molecules (A and B). In each molecule, the pyrrolidine ring adopts an envelope conformation with a methylene C atom as the flap atom. In molecule A, the central thiazole ring makes a dihedral angle of 36.69 (11)° with the adjacent phenyl ring, whereas the corresponding angle is 36.85 (12)° in molecule B. The pyrrolidine ring is slightly twisted from the thiazole ring, with C—N—C—N torsion angles of 4.8 (3) and 3.0 (4)° in molecules A and B, respectively. In the crystal, C—H...π and π–π [centroid-to-centroid distance = 3.7539 (14) Å] interactions are observed. The crystal studied was a pseudo-merohedral twin with twin law (-100 0-10 101) and a refined component ratio of 0.7188 (5):0.2812 (5).
N′2,N′5-Bis[(E)-2-hydroxybenzylidene]-3,4-dimethylthiophene-2,5-dicarbohydrazide
Authors: Zhang Shao-Lin , Zhang Ling , Wen Qin-Mei , Geng Rong-Xia , Zhou Cheng-He
Published: May 2012

In the title molecule, C22H20N4O4S, both C=N bonds are in an E conformation. The benzene rings form dihedral angles of 12.10 (13) and 25.17 (12)° with the thiophene ring. The dihedral angle between the two benzene rings is 17.59 (14)°. There are two intramolecular O—H...N hydrogen bonds. In the crystal, N—H...O hydrogen bonds connect molecules into chains along [010].
1-Methyl-3-(2-methylphenyl)-3a-nitro-1,2,3,3a,4,9b-hexahydrochromeno[4,3-b]pyrrole
Authors: Sundaramoorthy S. , Sivakumar N. , Bakthadoss M. , Velmurugan D.
Published: May 2012

The asymmetric unit of the title compound, C19H20N2O3, contains two independent molecules in both of which the pyrrolidine ring adopts an envelope conformation, but with a C atom as the flap in one molecule and the N atom in the other. The pyran ring adopts a half-chair conformation in both molecules. In the crystal, molecules are linked via C—H...O hydrogen bonds and C—H...π interactions.
4-Methoxy-N′-(3-nitrobenzylidene)benzohydrazide
Authors: Hou Jin-Long , Bi Ye
Published: May 2012

In the title compound, C15H13N3O4, the dihedral angle between the benzene rings is 3.1 (3)°. The molecule displays an E conformation about the C=N bond. In the crystal, molecules are linked via N—H...O hydrogen bonds, generating chains that propagate along the b-axis direction. There is also a C—H...O interaction present.
2-[(E)-3,4-Dimethoxybenzylidene]hydrazinecarboxamide
Authors: Tahir M. Nawaz , Umar M. Naveed , Ali Akbar , Shad Hazoor Ahmad
Published: May 2012

In the title compound, C10H13N3O3, the 3,4-dimethoxybenzylidene and hydrazinecarboxamide groups are oriented at a dihedral angle of 53.82 (6)° and an intramolecular N—H...N hydrogen bond generates an S(5) ring motif. In the crystal, molecules are linked by N—H...O hydrogen bonds into sheets propagating in (-201), which feature R
1
2(5), R
2
2(8) and R
2
4(14) loops.
Cinnarizinium picrate
Authors: Song Yanxi , Chidan Kumar C. S. , Nethravathi G. B. , Naveen S. , Li Hongqi
Published: May 2012

In the title salt {systematic name: 4-diphenylmethyl-1-[(E)-3-phenylprop-2-en-1-yl]piperazin-1-ium 2,4,6-trinitrophenolate), C26H29N2
+·C6H2N3O7
−, the cinnarizinium cation is protonated at the piperazine N atom connected to the styrenylmethyl group; the piperazine ring adopts a distorted chair conformaiton. In the crystal, bifurcated N—H...(O,O) hydrogen bonds link the components into two-ion aggregates.
6-Chloro-2-phenyl-3-(2-phenylethynyl)quinoxaline
Authors: Ouyang Xi-Lin , Ouyang Miao , Huang Shi-Wen
Published: May 2012

In the title compound, C22H13ClN2, the quinoxaline ring system is close to planar [maximum deviation = 0.061 (2) Å]. The phenyl ring at the 2-position and the phenyl ring of the phenylethynyl substituent make dihedral angles of 49.32 (7) and 11.99 (7) °, respectively, with the quinoxaline mean plane. The two phenyl rings are inclined to one another by 61.27 (9)°. In the crystal, molecules are linked by C—H...π and π–π interactions [centroid–centroid distances = 3.6210 (12) and 3.8091 (12) Å].
Quetiapine N-oxide–fumaric acid (2/1)
Authors: Shen Jin , Qian Jing-Jing , Wu Su-Xiang , Gu Jian-Ming , Hu Xiu-Rong
Published: May 2012

The title compound (systematic name: 2-{2-[4-(dibenzo[b,f][1,4]thiazepin-11-yl)piperazin-1-yl 1-oxide]ethoxy}ethanol–fumaric acid (2/1)), C21H25N3O3S·0.5C4H4O4, is one of the oxidation products of quetiapine hemifumaric acid. In the tricyclic fragment, the central thiazepine ring displays a boat conformation and the benzene rings are inclined to each other at a dihedral angle of 72.0 (2)°. The piperazine ring adopts a chair conformation with its ethoxyethanol side chain oriented equatorially. In addition to the main molecule, the asymmetric unit contains one-half molecule of fumaric acid, the complete molecule being generated by inversion symmetry. In the crystal, O—H...O hydrogen bonds link the components into corrugated layers parallel to bc plane.
catena-Poly[[tetrakis(hexamethylphosphoramide-κO)bis(nitrato-κ2
O,O′)lutetium(III)] [silver(I)-di-μ-sulfido-tungstate(VI)-di-μ-sulfido]]
Authors: Zhang Jinfang
Published: May 2012

In the title compound, {[Lu(NO3)2(C6H18N3OP)4][AgWS4]}
n
, hexamethylphosphoramide (hmp), tetrathiotungstate, silver iodide and lutetium nitrate were self-assembled, forming an anionic {[AgWS4]−}
n
chain extending parallel to [001]. The LuIII atom in the cation is coordinated by eight O atoms from two nitrate groups and four hmp ligands in a distorted square-antiprismatic geometry. Together with the two nitrate groups, the cation is monovalent, which leads to the anionic chain having a [WS4Ag] repeat unit. The polymeric anionic chain has a distorted linear configuration with W—Ag—W and Ag—W—Ag angles of 161.66 (2) and 153.503 (12)°, respectively. The title complex is isotypic with the Y, Yb, Eu, Nd, La, Dy and Sm analogues.
[4,6-Dimethylpyrimidine-2(1H)-thione-κS]iodidobis(triphenylphosphane-κP)copper(I)
Authors: Pakawatchai Chaveng , Wattanakanjana Yupa , Choto Patcharanan , Nimthong Ruthairat
Published: May 2012

In the mononuclear title complex, [CuI(C6H8N2S)(C18H15P)2], the CuI ion is in a slightly distorted tetrahedral coordination geometry formed by two P atoms from two triphenylphosphane ligands, one S atom from a 4,6-dimethylpyrimidine-2(1H)-thione ligand and one iodide ion. There is an intramolecular N—H...I hydrogen bond. In the crystal, π–π stacking interactions [centroid–centroid distance = 3.594 (1) Å] are observed.
5-[(4-Ethoxyanilino)methyl]-N-(2-fluorophenyl)-6-methyl-2-phenylpyrimidin-4-amine
Authors: Cieplik Jerzy , Stolarczyk Marcin , Bryndal Iwona , Lis Tadeusz
Published: May 2012

The asymmetric unit of the title compound, C26H25FN4O, consists of two symmetry-independent molecules, denoted A and B. The conformation of each molecule is mainly determined by an intramolecular N—H...N hydrogen bond, which closes a six-membered ring. The dihedral angles between the pyrimidine ring and the phenyl, fluorophenyl and ethoxyphenyl rings are 15.4 (2), 28.4 (2) and 77.5 (2)°, respectively, in molecule A, and 15.9 (2), 2.7 (2) and 61.8 (2)° in molecule B. Intermolecular N—H...N hydrogen bonds and π–π stacking interactions between pyrimidine rings [centroid–centroid distance = 3.692 (4) Å] connect molecules A and B into dimers and C—H...O hydrogen bonds link the dimers into zigzag chains along [011]. The (4-ethoxyanilino)methyl group of the B molecule is disordered over two sets of sites, the occupancy factor for the major component being 0.900 (2).
(E)-2-Cyano-N′-(1,2,3,4-tetrahydronaphthalen-1-ylidene)acetohydrazide
Authors: Al-Omar Mohamed A. , Khalifa Nagy M. , Ghabbour Hazem A. , Chia Tze Shyang , Fun Hoong-Kun
Published: May 2012

In the title compound, C13H13N3O, the tetrahydrobenzene ring adopts a half-boat (envelope) conformation. The mean plane of the tetrahydronaphthalene ring system forms a dihedral angle of 9.56 (6)° with the mean plane of the cyanoacetohydrazide group. In the crystal, inversion dimers linked by pairs of N—H...O hydrogen bonds generate R
2
2(8) loops. The dimers are connected by C—H...N hydrogen bonds into a chain propagating along [101]. The crystal packing also features C—H...π interactions.
Dimethyl[(E)-(2-nitromethylidene-1,3-dithiolan-4-yl)methyl]amine
Authors: Yang Shuang-Hua , Zhai Zhi-Wei
Published: May 2012

In the title compound, C7H12N2O2S2, the conformation of the dithiacyclopentane ring is a half-chair, with a total puckering amplitude Q
T = 0.473 (5) Å. Intermolecular C—H...N and C—H...O interactions help to establish the packing.