bluuebunny/crossref_metadata_2025 huggingface dataset:
IFT trains in different stages of assembly queue at the ciliary base for consecutive release into the cilium
Authors: Wingfield Jenna L , Mengoni Ilaria , Bomberger Heather , Jiang Yu-Yang , Walsh Jonathon D , Brown Jason M , Picariello Tyler , Cochran Deborah A , Zhu Bing , Pan Junmin , Eggenschwiler Jonathan , Gaertig Jacek , Witman George B , Kner Peter , Lechtreck Karl
Published: May 2017

Intraflagellar transport (IFT) trains, multimegadalton assemblies of IFT proteins and motors, traffic proteins in cilia. To study how trains assemble, we employed fluorescence protein-tagged IFT proteins in Chlamydomonas reinhardtii. IFT-A and motor proteins are recruited from the cell body to the basal body pool, assembled into trains, move through the cilium, and disperse back into the cell body. In contrast to this ‘open’ system, IFT-B proteins from retrograde trains reenter the pool and a portion is reused directly in anterograde trains indicating a ‘semi-open’ system. Similar IFT systems were also observed in Tetrahymena thermophila and IMCD3 cells. FRAP analysis indicated that IFT proteins and motors of a given train are sequentially recruited to the basal bodies. IFT dynein and tubulin cargoes are loaded briefly before the trains depart. We conclude that the pool contains IFT trains in multiple stages of assembly queuing for successive release into the cilium upon completion.
Fire‐induced albedo change and surface radiative forcing in sub‐Saharan Africa savanna ecosystems: Implications for the energy balance
Authors: Dintwe Kebonye , Okin Gregory S. , Xue Yongkang
Published: May 2017

Surface albedo is a critical parameter that controls surface energy balance. In dryland ecosystems, fires play a significant role in decreasing surface albedo, resulting in positive radiative forcing. Here we investigate the long‐term effect of fire on surface albedo. We devised a method to calculate short‐, medium‐, and long‐term effect of fire‐induced radiative forcing and their relative effects on energy balance. We used Moderate Resolution Imaging Spectroradiometer (MODIS) data in our analysis, covering different vegetation classes in sub‐Saharan Africa (SSA). Our analysis indicated that mean short‐term fire‐induced albedo change in SSA was −0.022, −0.035, and −0.041 for savannas, shrubland, and grasslands, respectively. At regional scale, mean fire‐induced albedo change in savannas was −0.018 and −0.024 for northern sub‐Saharan of Africa and the southern hemisphere Africa, respectively. The short‐term mean fire‐induced radiative forcing in burned areas in sub‐Saharan Africa (SSA) was 5.41 W m−2, which contributed continental and global radiative forcings of 0.25 and 0.058 W m−2, respectively. The impact of fire in surface albedo has long‐lasting effects that varies with vegetation type. The long‐term energetic effects of fire‐induced albedo change and associated radiative forcing were, on average, more than 19 times greater across SSA than the short‐term effects, suggesting that fires exerted far more radiative forcing than previously thought. Taking into account the actual duration of fire's effect on surface albedo, we conclude that the contribution of SSA fires, globally and throughout the year, is ~0.12 W m−2. These findings provide crucial information on possible impact of fire on regional climate variability.
Interactive genetic algorithm for user‐centered design of distributed conservation practices in a watershed: An examination of user preferences in objective space and user behavior
Authors: Piemonti Adriana Debora , Babbar‐Sebens Meghna , Mukhopadhyay Snehasis , Kleinberg Austin
Published: May 2017

Interactive Genetic Algorithms (IGA) are advanced human‐in‐the‐loop optimization methods that enable humans to give feedback, based on their subjective and unquantified preferences and knowledge, during the algorithm's search process. While these methods are gaining popularity in multiple fields, there is a critical lack of data and analyses on (a) the nature of interactions of different humans with interfaces of decision support systems (DSS) that employ IGA in water resources planning problems and on (b) the effect of human feedback on the algorithm's ability to search for design alternatives desirable to end‐users. In this paper, we present results and analyses of observational experiments in which different human participants (surrogates and stakeholders) interacted with an IGA‐based, watershed DSS called WRESTORE to identify plans of conservation practices in a watershed. The main goal of this paper is to evaluate how the IGA adapts its search process in the objective space to a user's feedback, and identify whether any similarities exist in the objective space of plans found by different participants. Some participants focused on the entire watershed, while others focused only on specific local subbasins. Additionally, two different hydrology models were used to identify any potential differences in interactive search outcomes that could arise from differences in the numerical values of benefits displayed to participants. Results indicate that stakeholders, in comparison to their surrogates, were more likely to use multiple features of the DSS interface to collect information before giving feedback, and dissimilarities existed among participants in the objective space of design alternatives.
Photoemission and electrostatic potentials on the dayside lunar surface in the terrestrial magnetotail lobes
Authors: Harada Y. , Poppe A. R. , Halekas J. S. , Chamberlin P. C. , McFadden J. P.
Published: May 2017

Despite the need to accurately predict and assess the lunar electrostatic environment in all ambient conditions that the Moon encounters, photoemission and electrostatic potentials on the dayside lunar surface in the terrestrial magnetotail lobes remain poorly characterized. We study characteristics and variabilities of lunar photoelectron energy spectra by utilizing Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS) and Apollo measurements in combination with the Flare Irradiance Spectral Model (FISM). We confirm that the photoelectron spectral shapes are consistent between ARTEMIS and Apollo and that the photoelectron flux is linearly correlated with the FISM solar photon flux. We develop an observation‐based model of lunar photoelectron energy distributions, thereby deriving the current balance surface potential. The model predicts that dayside lunar surface potentials in the tail lobes (typically tens of volts) could increase by a factor of 2–3 during strong solar flares.
Mantle transition zone discontinuities beneath the Indochina Peninsula: Implications for slab subduction and mantle upwelling
Authors: Yu Youqiang , Gao Stephen S. , Liu Kelly H. , Yang Ting , Xue Mei , Le Khanh Phon
Published: May 2017

While the northward indentation of the Indian into Eurasian plates has been intensively investigated, its oblique subduction beneath the Indochina Peninsula (ICP) and the role it played on mantle structure and dynamics remain enigmatic. In this first regional‐scale receiver function study of the mantle transition zone (MTZ) discontinuities beneath the ICP and its surrounding areas, we stack ∼12,000 receiver functions recorded at 33 stations using a non–plane wave common‐conversion‐point stacking technique. Systematic spatial variations of MTZ thickness with departures between −21 and +24 km from the globally averaged value are revealed, providing independent evidence for the presence of slab segments in the MTZ beneath the central and a slab window beneath the western ICP. The results also support the existence of broad mantle upwelling adjacent to the eastern edge of the slab segments, which might be responsible for the widespread Cenozoic volcanisms and pervasively observed upper mantle low velocities in the area.
Independent evolution of stratospheric temperatures in Jupiter's northern and southern auroral regions from 2014 to 2016
Authors: Sinclair J. A. , Orton G. S. , Greathouse T. K. , Fletcher L. N. , Tao C. , Gladstone G. R. , Adriani A. , Dunn W. , Moses J. I. , Hue V. , Irwin P. G. J. , Melin H. , Giles R. S.
Published: May 2017

We present retrievals of the vertical temperature profile of Jupiter's high latitudes from Infrared Telescope Facility‐Texas Echelon Cross Echelle Spectrograph measurements acquired on 10–11 December 2014 and 30 April to 1 May 2016. Over this time range, 1 mbar temperature in Jupiter's northern and southern auroral regions exhibited independent evolution. The northern auroral hot spot exhibited negligible net change in temperature at 1 mbar and its longitudinal position remained fixed at 180°W (System III), whereas the southern auroral hot spot exhibited a net increase in temperature of 11.1 ± 5.2 K at 0.98 mbar and its longitudinal orientation moved west by approximately 30°. This southern auroral stratospheric temperature increase might be related to (1) near‐contemporaneous brightening of the southern auroral ultraviolet/near‐infrared
emission measured by the Juno spacecraft and (2) an increase in the solar dynamical pressure in the preceding 3 days. We therefore suggest that 1 mbar temperature in the southern auroral region might be modified by higher‐energy charged particle precipitation.
Evidence for rapid topographic evolution and crater degradation on Mercury from simple crater morphometry
Authors: Fassett Caleb I. , Crowley Malinda C. , Leight Clarissa , Dyar M. Darby , Minton David A. , Hirabayashi Masatoshi , Thomson Bradley J. , Watters Wesley A.
Published: May 2017

Examining the topography of impact craters and their evolution with time is useful for assessing how fast planetary surfaces evolve. Here, new measurements of depth/diameter (d/D) ratios for 204 craters of 2.5 to 5 km in diameter superposed on Mercury's smooth plains are reported. The median d/D is 0.13, much lower than expected for newly formed simple craters (~0.21). In comparison, lunar craters that postdate the maria are much less modified, and the median crater in the same size range has a d/D ratio that is nearly indistinguishable from the fresh value. This difference in crater degradation is remarkable given that Mercury's smooth plains and the lunar maria likely have ages that are comparable, if not identical. Applying a topographic diffusion model, these results imply that crater degradation is faster by a factor of approximately two on Mercury than on the Moon, suggesting more rapid landform evolution on Mercury at all scales.
Variability and trends in surface seawater pCO2 and CO2 flux in the Pacific Ocean
Authors: Sutton A. J. , Wanninkhof R. , Sabine C. L. , Feely R. A. , Cronin M. F. , Weller R. A.
Published: May 2017

Variability and change in the ocean sink of anthropogenic carbon dioxide (CO2) have implications for future climate and ocean acidification. Measurements of surface seawater CO2 partial pressure (pCO2) and wind speed from moored platforms are used to calculate high‐resolution CO2 flux time series. Here we use the moored CO2 fluxes to examine variability and its drivers over a range of time scales at four locations in the Pacific Ocean. There are significant surface seawater pCO2, salinity, and wind speed trends in the North Pacific subtropical gyre, especially during winter and spring, which reduce CO2 uptake over the 10 year record of this study. Starting in late 2013, elevated seawater pCO2 values driven by warm anomalies cause this region to be a net annual CO2 source for the first time in the observational record, demonstrating how climate forcing can influence the timing of an ocean region shift from CO2 sink to source.
Gravity wave control on ESF day‐to‐day variability: An empirical approach
Authors: Aswathy R. P. , Manju G.
Published: May 2017

The gravity wave control on the daily variation in nighttime ionization irregularity occurrence is studied using ionosonde data for the period 2002–2007 at magnetic equatorial location Trivandrum. Recent studies during low solar activity period have revealed that the seed perturbations should have the threshold amplitude required to trigger equatorial spread F (ESF), at a particular altitude and that this threshold amplitude undergoes seasonal and solar cycle changes. In the present study, the altitude variation of the threshold seed perturbations is examined for autumnal equinox of different years. Thereafter, a unique empirical model, incorporating the electrodynamical effects and the gravity wave modulation, is developed. Using the model the threshold curve for autumnal equinox season of any year may be delineated if the solar flux index (F10.7) is known. The empirical model is validated using the data for high, moderate, and low solar epochs in 2001, 2004, and 1995, respectively. This model has the potential to be developed further, to forecast ESF incidence, if the base height of ionosphere is in the altitude region where electrodynamics controls the occurrence of ESF. ESF irregularities are harmful for communication and navigation systems, and therefore, research is ongoing globally to predict them. In this context, this study is crucial for evolving a methodology to predict communication as well as navigation outages.
Morphology of ionospheric F2 region variability associated with sudden stratospheric warmings
Authors: Gupta Sumedha , Upadhayaya A. K.
Published: May 2017

The effect of sudden stratospheric warming (SSW) on the F2 region ionosphere has been extensively analyzed for the major event of year 2009, apart from a few reports on other major and minor events. Morphology of ionospheric responses during SSW can be better comprehended by analyzing such warming events under different solar, geomagnetic, and meteorological conditions. We investigate the features of F2 region variability following the SSW events of 2010, 2011, 2012, 2013, 2014, 2015, and 2016, using ionosonde data from the Asian region covering a broad latitudinal range from 26.6°N to 45.1°N. We find perceptible ionospheric variations in electron densities during these warming events which is accompanied by a large variation of ~117% within enhancements, as compared to a meagre variation of ~11% within depressions, during these events. We also examine 6 months data at these latitudes and longitudes and find that the maximum and minimum variations in F2 layer critical frequency are observed during each SSW period. The influence of quasi‐stationary 16 day planetary waves is seen during these SSW events. Further, a recently proposed parameter “SSW integrated strength” by Vieira et al. (2017) to characterize SSW event with respect to ionosphere is also examined. It is seen that it does not fit well for these seven SSW events at these latitudes and longitudes.
Statistical characterization of the large‐scale structure of the subauroral polarization stream
Authors: Kunduri B. S. R. , Baker J. B. H. , Ruohoniemi J. M. , Thomas E. G. , Shepherd S. G. , Sterne K. T.
Published: May 2017

The subauroral polarization streams (SAPS) are latitudinally narrow regions of westward directed flows observed equatorward of the evening sector auroral oval. Previous studies have shown that SAPS generally occur during geomagnetically disturbed conditions and exhibit a strong dependence on geomagnetic activity. In this paper, we present the first comprehensive statistical study of SAPS using measurements from the U.S. midlatitude Super Dual Auroral Radar Network (SuperDARN) radars. The study period spans January 2011 to December 2014, and the results show that SuperDARN radars observe SAPS over a broad range of activity levels spanning storm time and nonstorm conditions. During relatively quiet conditions (−10 nT <Dst< 10 nT) SAPS occur 15% of the time and tend to be localized to the midnight sector and centered above 60° magnetic latitude. As the activity level increases, the peak SAPS location shifts equatorward and duskward. During moderately disturbed conditions (−75 nT <Dst <− 50 nT) SAPS occur 87% of the time and tend to be centered at 20 magnetic local time (MLT) and below 60° magnetic latitude. This behavior has been encoded into a new empirical model which uses Dst as input to estimate the probability of SAPS occurrence at a given magnetic latitude and MLT. Similar to some previous studies, the variation of SAPS speed with MLT is found to be nearly linear at low to moderate levels of geomagnetic activity but becomes increasingly nonlinear near dusk sector as geomagnetic activity increases. We interpret this behavior as indicative of active ionosphere‐thermosphere feedback playing an important role in modulating SAPS speeds.
Quantification of marine aerosol subgrid variability and its correlation with clouds based on high‐resolution regional modeling
Authors: Lin Guangxing , Qian Yun , Yan Huiping , Zhao Chun , Ghan Steven J. , Easter Richard , Zhang Kai
Published: May 2017

One limitation of most global climate models (GCMs) is that with the horizontal resolutions they typically employ, they cannot resolve the subgrid variability (SGV) of clouds and aerosols, adding extra uncertainties to the aerosol radiative forcing estimation. To inform the development of an aerosol subgrid variability parameterization, here we analyze the aerosol SGV over the southern Pacific Ocean simulated by the high‐resolution Weather Research and Forecasting model coupled to Chemistry. We find that within a typical GCM grid, the aerosol mass subgrid standard deviation is 15% of the grid‐box mean mass near the surface on a 1 month mean basis. The fraction can increase to 50% in the free troposphere. The relationships between the sea‐salt mass concentration, meteorological variables, and sea‐salt emission rate are investigated in both the clear and cloudy portion. Under clear‐sky conditions, marine aerosol subgrid standard deviation is highly correlated with the standard deviations of vertical velocity, cloud water mixing ratio, and sea‐salt emission rates near the surface. It is also strongly connected to the grid box mean aerosol in the free troposphere (between 2 km and 4 km). In the cloudy area, interstitial sea‐salt aerosol mass concentrations are smaller, but higher correlation is found between the subgrid standard deviations of aerosol mass and vertical velocity. Additionally, we find that decreasing the model grid resolution can reduce the marine aerosol SGV but strengthen the correlations between the aerosol SGV and the total water mixing ratio (sum of water vapor, cloud liquid, and cloud ice mixing ratios).
Benzylalkohol [MAK Value Documentation in German language, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: May 2017

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated benzyl alcohol [100‐51‐6] to derive a maximum concentration at the workplace (MAK value), considering all toxicity endpoints. Available study reports and publications are described in detail.

Benzyl alcohol is irritating to the eyes and the airways. In a 4‐week inhalation study in rats, microscopic lesions in the airways, especially in the lung, occurred at 1072 mg/m3. The NAEC is estimated to be 300 mg/m3, a concentration at which benzyl alcohol can occur as vapour, corresponding to 67 ml/m3. A MAK value of 5 ml/m3has been derived. As local effects are critical, benzyl alcohol is classified in Peak Limitation Category I with an excursion factor of 2.

In developmental toxicity studies with benzyl alcohol in mice, foetotoxic effects occurred at 750 mg/kg body weight and day in the presence of marked maternal toxicity. The NOAEL was 550 mg/kg body weight and day; however, teratogenicity was not examined. Benzoic acid is the main metabolite of benzyl alcohol. Considering the developmental toxicity studies with sodium benzoate, the differences between the NOAEL for rats, mice, rabbits and hamsters scaled to an inhalation concentration at the workplace and the MAK value are considered so large that damage to the embryo or foetus is unlikely when the MAK value is observed. Therefore, benzyl alcohol is classified in Pregnancy Risk Group C.

Benzyl alcohol is not regarded to be genotoxic or carcinogenic. Sensitization is not expected as benzyl alcohol was not a contact sensitizer in a local lymph node assay and there were no conclusive positive clinical findings of sensitizing effects on the skin. Skin contact is expected to contribute significantly to the systemic toxicity. Therefore, benzyl alcohol is designated with an “H”.
N‐Methylanilin [MAK Value Documentation in German language, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: May 2017

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the workplace (MAK value) of N‐methylaniline [100‐61‐8] considering all toxicity endpoints. Available publications and unpublished study reports are described in detail. Critical effect is the formation of methaemoglobin (MetHb). Adequate data in humans to derive a MAK value are not available; thus, data with rats are used. In rats, N‐methylaniline forms MetHb 2.7 times more efficiently than aniline. Based on the MAK value for aniline of 2 ml/m3, the MAK value for N‐methylaniline of 0.5 ml/m3is confirmed. As the critical effect is systemic, Peak Limitation Category II is retained; as the half‐life in blood is unknown, the default excursion factor of 2 is also retained. N‐Methylaniline remains in Pregnancy Risk Group D because developmental toxicity studies are lacking. The substance does not induce mutations in bacteria, but is clastogenic in mammalian cells. Studies on genotoxicity in vivo have not been performed. Adequate data to assess the carcinogenic potential of N‐methylaniline are not available. Data for the metabolite aniline are used to assess the carcinogenic potential of N‐methylaniline. Aniline induces spleen tumours in rats, but not in mice. The putative mode of action is an indirect tumour development by induction of MetHb and haemolytic effects which result in erythrocyte toxicity and its consequences, perturbations in iron metabolism in the spleen. The metabolites phenylhydroxylamine and nitrosobenzene are mainly responsible for the erythrocyte toxicity of aniline. As nitrosobenzene is also a metabolite of N‐methylaniline, a similar mode of action has to be assumed for N‐methylaniline. Therefore, a non‐genotoxic mode of action is of prime importance and genotoxic effects play at most a minor part provided the MAK and BAT values are observed. Thus, N‐methylaniline is classified as a suspected carcinogen in Carcinogen Category 3B. Skin contact may contribute significantly to systemic toxicity and the “H” notation is retained. There are no clinical data concerning the sensitizing activity of the substance. Results of a local lymph node assay in mice were negative.
2,4,6‐Tribromphenol [MAK Value Documentation in German language, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: May 2017

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated 2,4,6‐tribromophenol [118‐79‐6] to derive a maximum concentration at the workplace (MAK value), considering all toxicity endpoints. Available study reports and publications are described in detail.

2,4,6‐Tribromophenol is irritating to the rabbit eye. Therefore, irritation of the respiratory tract has to be assumed; however, the only available repeated dose inhalation study in rats is of limited validity. The lowest NOAEL for systemic toxicity in an oral study in rats was 100 mg/kg body weight and day. Beginning from 300 mg/kg body weight and day, increased creatinine levels in the blood of male rats and intense salivation in male and female animals were observed. Due to the irritant potential and the lack of a valid inhalation study, no MAK value could be set and 2,4,6‐tribromophenol is classified in Section II b of the List of MAK and BAT Values.

In a reproduction and developmental toxicity screening test the NOAEL for fertility and foetotoxicity was 300 mg/kg KG body weight and day. Teratogenicity was not investigated.

2,4,6‐Tribromophenol is not regarded to be genotoxic or carcinogenic. Sensitization is not expected due to limited animal studies and human experience. Skin contact is not expected to contribute significantly to the systemic toxicity.
Tetrachlorethen [MAK Value Documentation in German language, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: May 2017

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated tetrachloroethylene [127‐18‐4] to derive a maximum concentration at the workplace (MAK value), considering all toxicity endpoints. Available study reports and publications are described in detail.

Results from human studies do not point to a genotoxic potential of tetrachloroethylene. In vitro and in vivo studies in mammalian cells do not show a distinct genotoxic potential. From epidemiologic and animal studies there is concern that tetrachloroethylene could be carcinogenic for humans; therefore, tetrachloroethylene has been classified in Carcinogen Category 3B. However, since carcinogenic effects are judged to be not predominantly caused by genotoxic mechanisms, a MAK value can be derived.

Neurotoxicity is considered the most sensitive endpoint for tetrachloroethylene. In volunteers, repeated daily 4‐hour inhalation exposure caused small but significant effects on visual evoked potentials. The NOAEC was 10 ml/m
3
, but as only weak effects were observed at the LOAEC of 50 ml/m
3
, 20 ml/m
3
is regarded as the NAEC. As a doubling of uptake is expected under workplace conditions, a MAK value of 10 ml/m
3
has been set. As the critical effect is systemic, tetrachloroethylene is assigned to Peak Limitation Category II. The default excursion factor of 2 is set as the half‐life in the central nervous system is unknown.

There is limited evidence suggesting that women working in a dry‐cleaner have an increased risk of spontaneous abortion. But the limited validity of the studies is not sufficient to prove a causal relationship. In developmental toxicity studies, NOAECs for developmental toxicity of 65 and 217 ml/m
3
in rats, 500 ml/m
3
in rabbits, and a LOAEC of 217 ml/m
3
in mice were obtained. The NOAEC for behavioural toxicity in the offspring of treated rats was 100 ml/m
3
. The differences between these NOAECs as well as the LOAEC and the MAK value are considered so large that damage to the embryo or foetus is unlikely when the MAK value is observed. Therefore, tetrachloroethylene is classified in Pregnancy Risk Group C.

Sensitization is not expected due to results of animal studies and experience in humans. Skin contact is expected to contribute significantly to the systemic toxicity of tetrachloroethylene. Therefore, designation with an “H” is confirmed.
4‐
tert
‐Octylphenol [MAK Value Documentation in German language, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: May 2017

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated the developmental toxicity of 4‐tert‐octylphenol [140‐66‐9]. In 2015, the maximum concentration at the workplace (MAK value) for 4‐tert‐octylphenol was set at 0.5 ml/m
3
(4.3 mg/m
3
).

In a screening study in rats with gavage administration, litter size and body weight of the progeny at postnatal day 4 was reduced at 500 mg/kg body weight and day, accompanied by maternal toxicity. A NOAEL for foetotoxicity of 250 mg/kg body weight and day was derived, corresponding to a concentration of 28.5 ml/m
3
at the workplace. In a 2‐generation feeding study in rats, foetotoxicity was not observed until postnatal day 13. At 111–369 mg/kg body weight and day, vaginal opening or preputial separation of the F2 progeny was delayed. A NOAEL of 10.9–32.6 mg/kg body weight and day was derived for postnatal developmental toxicity in rats, corresponding to 1.2–3.7 ml/m
3
. Because adequate studies of prenatal developmental toxicity over the complete period of organogenesis are lacking, data are not sufficient for classification and 4‐tert‐octylphenol is assigned to Pregnancy Risk Group D.
Methylstyrol (Vinyltoluol) (alle Isomere) [MAK Value Documentation in German language, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: May 2017

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated methyl styrene [25013‐15‐4] considering all toxicological endpoints and revised the maximum concentration at the workplace (MAK value). Publications are described in detail.

In long‐term inhalation studies with methyl styrene, inflammation and hyperplasia were observed in nasal tissue of rats and mice with LOAECs of 100 ml/m3 and 10 ml/m3, respectively. As was shown with styrene, the reason for mice being more susceptible than rats is differences in the rates of phase I and phase II metabolism. While the rate of oxidation to the epoxide is almost the same in rats and mice, the detoxification via epoxide hydrolase and GSH‐transferase is about 10‐fold faster in rats than in mice. In human nasal tissue in vitro, oxidation of styrene is minimal but metabolization via epoxide hydrolase and GSH‐transferase occurs at almost the same rate as in rat nasal tissue. Therefore, humans are much less sensitive to nasal effects of styrene and this species difference is assumed to be the same for the similarly metabolized methyl styrene. The MAK value is derived from the LOAEC in rats and set at 20 ml methyl styrene/m3. Due to the local effect being critical, the substance is assigned to Peak Limitation Category I. As there was no sensory irritation in volunteers with methyl styrene at 50 ml/m3, the excursion factor is 2.

Methyl styrene has a limited genotoxic potential only at systemically toxic doses, and 2‐year carcinogenicity studies were negative.

Dermal absorption does not contribute significantly to the systemic toxicity and investigations in humans and animals do not indicate a significant sensitizing effect.

Because 3 studies on the developmental toxicity of methyl styrene are only available as summaries and the reason for the differing effects cannot be evaluated, methyl styrene is assigned to Pregnancy Risk Group D.
Ethylenglykoldinitrat [MAK Value Documentation in German language, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: May 2017

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the workplace (MAK value) of ethylene glycol dinitrate [628‐96‐6] of 0.05 ml/m3, considering all toxicity endpoints. A detailed description of the underlying studies is given.

The critical effect in volunteers after a 25‐minute exposure to 0.05 ml/m3of a mixture of ethylene glycol dinitrate and nitroglycerin was vasodilation, as indicated by the development of headaches or decreases in blood pressure. The effects were very slight. In occupational situations it is very difficult to assess the levels of exposure to ethylene glycol dinitrate that induce symptoms and effects, not only because exposure is usually to mixtures of organic nitrate esters, but also because of both respiratory tract and skin absorption of ethylene glycol dinitrate vapours. In workers, headaches were reported at nitroglycerin concentrations of 0.03 to 0.11 ml/m3with a NOAEC below 0.01 ml/m3nitroglycerin. Based on this data, the MAK value for nitroglycerin was established at 0.01 ml/m3. Because of the same mode of action and the similar LOAEC of the two substances, the MAK value for ethylene glycol dinitrate has been lowered to 0.01 ml/m3. The MAK value also applies to the sum of the concentrations of the two substances in the air. As systemic effects are critical, the assignment to Peak Limitation Category I and the excursion factor of 1, due to the short half‐life, are retained. Although there are no studies on developmental toxicity, ethylene glycol dinitrate is assigned to Pregnancy Risk Group C in analogy to nitroglycerin. No data are available for genotoxicity or carcinogenicity. Skin contact may contribute significantly to systemic toxicity and ethylene glycol dinitrate continues to be designated with an “H”. Sensitization is not expected from the limited data.
Nitroethan [MAK Value Documentation in German language, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: May 2017

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the workplace (MAK value) for nitroethane [79‐24‐3], considering the endpoints local and systemic toxicity as well as developmental toxicity. Nitroethane acts locally as well as systemically. A 13‐week study in rats and mice found significantly increased methaemoglobin levels accompanied by changes in the spleen as critical effects. A NOAEC was not obtained. Based on the LOAEC of 100 ml/m3and taking into consideration the higher sensitivity of humans and the possibility of effects increasing with time, the MAK value for nitroethane is lowered to 10 ml/m3. Degeneration, inflammation and hyperplasia of the olfactory epithelium occur at higher exposure concentrations. As the critical effect is systemic, the assignment to Peak Limitation Category II is retained as well as the excursion factor of 4. Because there are no studies on developmental toxicity with pure nitroethane, the assignment to Pregnancy Risk Group D is also confirmed. Skin contact may contribute significantly to systemic toxicity and nitroethane is designated with an “H”. Sensitization is not expected from the limited data.
Reforming Youth Facilities
Authors: Krisberg Barry A.
Published: May 2017

Research has found that juvenile corrections facilities may propel young people toward violence and further law breaking. Many incarcerated youth are exposed to very harsh conditions of confinement and to physical and sexual violence. Increasing, in the United States, the federal and state courts have found that juvenile facilities violate the Eighth Amendment of the US Constitution and other civil rights laws. There is a growing movement to fix juvenile corrections by diverting incarcerated young people to community‐based programs. The first and most dramatic example of these reforms occurred in Massachusetts in the early 1970s. Another example of positive reform happened in California, which has cut its youth incarceration rate by over 90%. California has made many improvements in the care of youngsters in its state facilities. The use of solitary confinement has been sharply limited, the use of force against youth has declined, and educational and counseling services have been expanded.
Manipulating Bubbles in Aqueous Environment via a Lubricant‐Infused Slippery Surface
Authors: Yu Cunming , Zhu Xuanbo , Li Kan , Cao Moyuan , Jiang Lei
Published: May 2017

Designing functional interfaces to control solid/fluid interactions has emerged as an indispensable strategy for developing advanced materials and optimizing current technologies. Surfaces exhibiting special wettability offer many paradigms for regulating fluid behavior in practical applications including oil–water separation and fog harvesting. Nevertheless, the flexible manipulation of air bubbles under water still has room for further exploration. Here, it is reported that the lubricant‐infused slippery (LIS) surface with water repellency is applicable to manipulate bubbles in an aqueous environment. On the basis of the sufficient bubble adhesion, the shaped LIS tracks can be used in guiding the bubble delivery and facilitating continuous bubble distribution. Through the incorporation of an asymmetrical structure into the LIS surface, a triangle‐shaped bubble holder is capable of controlling a single bubble with ease. Moreover, the LIS surface is integrated with a H2 microbubble evolving apparatus, demonstrating a potential method for in situ capture and delivery of microbubbles. The current finding reveals the meaningful interaction between underwater bubbles and the LIS surface, providing several examples for the applications of this bubble carrier, which should shed new light on the development of bubble‐controlling interfaces.
Remotely Controlled Microscale 3D Self‐Assembly Using Microwave Energy
Authors: Liu Chao , Schauff Joseph , Joung Daeha , Cho Jeong‐Hyun
Published: May 2017

A novel, remotely controlled assembly process is developed to create microscale, self‐assembled 3D structures using remote‐controlled microwave energy. A nanometer thick chromium (Cr) film absorbs electromagnetic microwaves and generates heat energy, which induces reflow of polymeric hinges. This leads to self‐assembly of microscale 3D cubic structures. Since this assembly process does not require direct contact with a heat source or chemicals, microscale actuations can be achieved in a remote location without physical contact, resulting in the powerful capability to manipulate the 3D assembly process in situations where the heat sources and the environment around the microstructures are not controllable and accessible. Multiple folding configurations of the microstructures can also be achieved simultaneously with a single microwave energy source by forming different Cr thicknesses adjacent to the polymer hinges. Thus, remote‐controlled self‐assembly using microwave energy might be applied for the development of 3D microscale‐sensors, ‐microbots, and ‐metamaterials.
Validation of a virtual reality simulator for the use of transvaginal ultrasonography in gynaecology and early pregnancy
Authors: Al‐Memar Maya , Saso Srdjan , Bobdiwala Shabnam , Ameye Lieveke , Guha Sharmistha , Joash Karen , Stalder Catriona , Sur Shyamaly , Moorthy Krishen , Timmerman Dirk , Bourne Tom
Published: May 2017

Introduction

The objective was to validate a virtual reality simulation ultrasound model as a tool for training in the use of transvaginal ultrasonography in gynaecology and early pregnancy.

Methods

Three separate groups consisting of novice and intermediate level residents as well as expert ultrasound examiners were recruited to the study. All were asked to answer a questionnaire regarding demographic data and ultrasound experience. They subsequently completed two modules: basic gynaecology and early pregnancy, followed by corresponding assessments using a high‐fidelity simulator (Scantrainer; Medaphor™, Cardiff, UK). Finally, the expert group completed an additional questionnaire about various elements of the simulator using a 5‐point Likert scale.

Results

Each group consisted of eight participants. Overall, the participants agreed that simulation played a role in training (Novices: 75% (n = 6); Intermediates: 100% (n = 8); Experts: 75% (n = 6)). For the degree of realism of the target objects in the gynaecology and early pregnancy module environments compared to a real‐patient environment, the simulator was rated satisfactory or very satisfactory by 88% (n = 7) and 75% (n = 6) of experts, respectively. All experts rated the overall usefulness of the content of the simulator for learning fundamental ultrasound technical skills compared to current training methods to be at least satisfactory. When reviewing the assessment scores, experts scored higher than non‐experts in gynaecology (P = 0.002) and early pregnancy modules (P = 0.03).

Discussion

Face, content and construct validity were demonstrated by the virtual reality ultrasound simulator, suggesting it may be an effective method for training ultrasound skills in gynaecology and early pregnancy to non‐expert residents.
Hydroxoiridium‐Catalyzed Hydroalkylation of Terminal Alkenes with Ureas by C(sp3)−H Bond Activation
Authors: Yamauchi Daisuke , Nishimura Takahiro , Yorimitsu Hideki
Published: May 2017

Direct alkylation of a methyl group, on di‐ and trisubstituted ureas, with terminal alkenes by C(sp3)−H bond activation proceeded in the presence of a hydroxoiridium/bisphosphine catalyst to give high yields of the corresponding addition products. The hydroxoiridium/bisphosphine complex generates an amidoiridium intermediate by reaction with ureas having an N−H bond.
Electronically Activated Organoboron Catalysts for Enantioselective Propargyl Addition to Trifluoromethyl Ketones
Authors: Mszar Nicholas W. , Mikus Malte S. , Torker Sebastian , Haeffner Fredrik , Hoveyda Amir H.
Published: May 2017

A broadly applicable, practical, scalable, efficient and highly α‐ and enantioselective method for addition of a silyl‐protected propargyl moiety to trifluoromethyl ketones has been developed. Reactions, promoted by 2.0 mol % of a catalyst that is derived in situ from a readily accessible aminophenol compound at ambient temperature, were complete after only 15 minutes at room temperature. The desired tertiary alcohols were isolated in up to 97 % yield and 98.5:1.5 enantiomeric ratio. Alkyl‐, alkenyl‐, alkynyl‐, aryl‐ or heteroaryl‐substituted trifluoromethyl ketones can be used. Utility is highlighted by application to a transformation that is relevant to enantioselective synthesis of BI 653048, a compound active against rheumatoid arthritis.
Superelectrophilic Behavior of an Anion Demonstrated by the Spontaneous Binding of Noble Gases to [B12Cl11]−
Authors: Rohdenburg Markus , Mayer Martin , Grellmann Max , Jenne Carsten , Borrmann Tobias , Kleemiss Florian , Azov Vladimir A. , Asmis Knut R. , Grabowsky Simon , Warneke Jonas
Published: May 2017

It is common and chemically intuitive to assign cations electrophilic and anions nucleophilic reactivity, respectively. Herein, we demonstrate a striking violation of this concept: The anion [B12Cl11]−spontaneously binds to the noble gases (Ngs) xenon and krypton at room temperature in a reaction that is typical of “superelectrophilic” dications. [B12Cl11Ng]−adducts, with Ng binding energies of 80 to 100 kJ mol−1, contain B−Ng bonds with a substantial degree of covalent interaction. The electrophilic nature of the [B12Cl11]−anion is confirmed spectroscopically by the observation of a blue shift of the CO stretching mode in the IR spectrum of [B12Cl11CO]−and theoretically by investigation of its electronic structure. The orientation of the electric field at the reactive site of [B12Cl11]−results in an energy barrier for the approach of polar molecules and facilitates the formation of Ng adducts that are not detected with reactive cations such as [C6H5]+. This introduces the new chemical concept of “dipole‐discriminating electrophilic anions.”
Co‐assembly of Patchy Polymeric Micelles and Protein Molecules
Authors: Fan Weijing , Liu Li , Zhao Hanying
Published: May 2017

The development in the synthesis and self‐assembly of patchy nanoparticles has resulted in the creation of complex hierarchical structures. Co‐assembly of polymeric nanoparticles and protein molecules combines the advantages of polymeric materials and biomolecules, and will produce new functional materials. Co‐assembly of positively charged patchy micelles and negatively charged bovine serum albumin (BSA) molecules is investigated. The patchy micelles, which were synthesized using block copolymer brushes as templates, leads to co‐assembly with protein molecules into vesicular structures. The average size of the assembled structures can be controlled by the molar ratio of BSA to patchy micelles. The assembled structures are dissociated in the presence of trypsin. The protein–polymer hybrid vesicles could find potential applications in medicine.
Pd‐SBT@MCM‐41: As an efficient, stable and recyclable organometallic catalyst for C‐C coupling reactions and synthesis of 5‐substituted tetrazoles
Authors: Nikoorazm Mohsen , Ghorbani‐Choghamarani Arash , Ghobadi Massoud , Massahi Shokofeh
Published: May 2017

A palladium S‐benzylisothiourea complex was anchored on functionalized MCM‐41 (Pd‐SBT@MCM‐41) and applied as efficient and reusable catalyst for the synthesis of 5‐substituted 1H–tetrazoles using [2 + 3] cycloaddition reaction of various organic nitriles with sodium azide (NaN3) in poly(ethylene glycol) (PEG) as green solvent. Also this catalyst was applied as an versatile organometallic catalyst for Suzuki cross‐coupling reaction of aryl halides and phenylboronic acid (PhB(OH)2) or sodium tetraphenyl borate (NaB(Ph)4). This nanocatalyst was characterized by thermal gravimetric analysis (TGA), X‐ray Diffraction (XRD), scanning electron microscopy (SEM), inductively Coupled Plasma (ICP) and N2 adsorption–desorption isotherms techniques. Recovery of the catalyst is easily achieved by centrifugation for several consecutive runs.
Master in oral biology program: A path to addressing the need for future dental educators
Authors: Jergenson Margaret A. , Barritt Laura C. , O'Kane Barbara J. , Norton Neil S.
Published: May 2017

In dental education, the anatomical sciences, which include gross anatomy, histology, embryology, and neuroanatomy, encompass an important component of the basic science curriculum. At Creighton University School of Dentistry, strength in anatomic science education has been coupled with a solid applicant pool to develop a novel Master of Science in Oral Biology, Anatomic Sciences track degree program. The program provides a heavy emphasis on developing teaching skills in predoctoral students as well as exposure to research processes to encourage the cohort to pursuing a career in academic dentistry. The individuals considered for this program are applicants for admission to the School of Dentistry that have not been accepted into the entering dental class for that year. The students undertake a two year curriculum, studying anatomic sciences with a special emphasis on teaching. The students also must complete a research project that requires a thesis. The students in the program are guaranteed acceptance to dental school upon successful completion of the program. After six years, the first ten students have received their Master of Science degrees and continued in dental school. The program is favorably viewed by the faculty and participating students. It is also considered successful by metrics. Nine of the ten graduates have said they would like to participate in academic dentistry in some capacity during their careers. Anat Sci Educ 10: 607–612. © 2017 American Association of Anatomists.
Advanced Silicon Chemistry in Australia: Forming Strong Links with Asia
Authors: Clarke Stephen , Nguyen Kim‐Anh Thi , Markovic Elda , Trout Neil , Ginic‐Markovic Milena , Matisons Janis , Owen Michael , Graiver Daniel , Wargadipura Agus Hadi Santosa , Habibie Sudirman , Gustiono Dwi , Yoo Bok Ryul , Mifsud Joe
Published: May 2017

This paper details Australian commercial and academic silicon research. Areas of interest include silicon metal, polysiloxane polymers, copolymers, cyclics, emulsions, microemulsions, silanes, silane coupling agents, sol‐gel chemistry and water‐treatments, porous silicon, polysiloxane degradation, silicon hydrogel contact lenses, silanolate synthesis, siloxane interfacial polymerisation, hydrosilylation, polysiloxane electrolytes for lithium ion batteries, silanes for PBX materials, octafunctionalized polyhedral oligomeric silsesquioxanes (POSS), POSS hybrids, sol‐gel hydrogenation catalysts, silane modification of silica, sol‐gel energy storage, silicate grout stabilisation, GeoPolymer concretes, aerogel insulating foams, “Phaco‐Ersatz” Accommodating Gel—Intraocular Lens technologies. Strong collaborative opportunities, in silicon, with Asia, exist with organisations such as: 1) The Asian Silicon Society and 2) The Agency for the Assessment and Application of Technology (BPPT) Indonesia.
Toward Benzobis(thiadiazole)‐based Diradicaloids
Authors: Liu Yi , Phan Hoa , Herng Tun Seng , Gopalakrishna Tullimilli Y. , Ding Jun , Wu Jishan
Published: May 2017

We theoretically predicted that acetylene‐bridged benzo[1,2‐c;4,5‐c′]bis[1,2,5]thiadiazole (BBT) oligomers would show a quick increase of diradical character with the extension of chain length. To validate the hypothesis, six stable BBT‐based diradicaloids were synthesized and fully characterized by X‐ray crystallographic analysis and various spectroscopic measurements. Three of them showed prominent paramagnetic activity at elevated temperatures due to thermal population from the open‐shell singlet ground state to triplet excited state. It was also found that substitution by electron‐donating triphenylamine groups at the termini promoted the diradical character and reduced the singlet–triplet energy gap, and at the same time, resulted in intense near‐infrared absorption.