bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial and temporal composition of the avifauna from small coastal wetlands and adjacent habitats in northwestern Baja California, Mexico
Authors: Ruiz-Campos G , Palacios E , Castillo-Guerrero JA , González-Guzmán S , Batche-González EH
Published: August 2017

We studied the spatial and temporal composition of the avifauna from 13 small coastal wetlands and adjacent habitats in northwestern Baja California, Mexico, between February and December 2002. A total of 17,978 individuals belonging to 187 species, 121 genera and 47 families were registered. The richest families in species were Anatidae (17), Scolopacidae (17) and Laridae (12). The wetlands showing the highest specific richness were El Rosario (126), Santo Tomás (107) and La Misión (95), which pooled represented 86% of the total avifauna. Seventy-six species (41%) were permanent residents, 73 (39%) seasonal visitors and 38 (20%) occasional visitors. On the basis of presence or absence of species, four groups of wetlands are distinguished: (a) San Simón, (b) La Salina, (c) El Descanso-El Ciprés, and (d) a group of nine sites that is subdivided into two branches with four and five localities each, one (d.1) consisting of San Telmo-Santo Tomás-El Rosario-La Misión and the other (d.2) of San Rafael-San Miguel-El Salado-Santo Domingo-Cantamar. The presence or absence of a permanent water body, the types of habitat and the presence or absence of anthropogenic influence at each locality were factors that contributed to the grouping of these wetlands. Specific richness and abundance were correlated with habitat diversity. Breeding evidence was documented for 20 species.
Low genetic differentiation among sardine populations, Sardinella aurita, from eastern Venezuela
Authors: De-Donato M , Mimbela-de-Loroño I , Ramírez I , Marín B
Published: August 2017

In view of the great importance of Sardinella aurita as a fisheries resource in the Caribbean region, we studied the genetic differentiation among the populations from Mochima, Gulf of Cariaco and Morro de Puerto Santo, eastern Venezuela, and compared the levels of variation and population subdivision with populations from the Mediterranean and Atlantic coast of Africa (previously reported). For this, we extracted DNA from 15 muscle samples for each population. A fragment containing the control region of the mitochondrial DNA was amplified and the restriction patterns were determined using restriction fragment length polymorphism (RFLP) analysis with the enzymes Taq I, Eco RI, Hae III and Alu I. The amplification of this region produced a fragment approximately 1000 bp long or, rarely, one of approximately 1100 bp long. No further difference was found through the RFLP analysis. The comparison of the Venezuelan populations produced FST values under 0.06 and the analysis of molecular variance showed no significant differences between them. This is an indication of very low genetic differentiation among these populations, so it is not possible to discard the presence of a panmictic population in this region. The comparison of the Venezuelan and Mediterranean populations produced very low FST values, while the comparison of the former with African populations from Mauritania, Senegal, Ivory Coast and Ghana produced FST values ten times larger.
Study of the dynamic behaviour of the Sancti Petri Channel, southwest coast of Spain
Authors: Vidal J , Tejedor B
Published: August 2017

The dynamic behaviour of the Sancti Petri tidal channel (southwest coast of Spain), which is open at both ends and connected to water bodies with different dynamic characteristics (Atlantic Ocean and Cádiz Bay), is studied herein. This singular estuary is characterized by double inflow-outflow extremes, the tide penetrating almost simultaneously through both ends with a small difference of amplitude. For this study, sea level recordings were obtained from different points throughout the channel and the corresponding harmonic constituents were determined. The results show that the phases of the semidiurnal tides increase from the mouths to a zone located in the vicinity of the channel´ s halfway point, while their amplitudes increase from the Atlantic Ocean to Cádiz Bay along the channel. A one-dimensional numerical model with geometry that is representative of the channel was used to reproduce the features observed for the semidiurnal and diurnal tidal constituents. The data supplied by the model were verified with values obtained at strategically chosen sites of the inner domain. The model developed may be used for operational predictions of tides in the study area, especially for the ports of Gallineras and Sancti Petri.
Empirical relations to estimate underwater PAR attenuation in San Quintín Bay using Secchi depth and horizontal sighting range
Authors: Montes-Hugo MA , Álvarez-Borrego S
Published: August 2017

Empirical relationships to estimate vertical attenuation coefficient of photosynthetically available radiation (KPAR) using Secchi disk, vertical black disk, and horizontal sighting ranges for San Quintín Bay, Baja California, were developed. Radiometric PAR profiles were used to calculate KPAR. Vertical (ZD) and horizontal (HS) sighting ranges were measured with white (Secchi depth or ZSD, HSW) and black (ZBD, HSB) targets. The empirical power models KPAR = 1.48 ZSD–1.16, KPAR = 0.87 ZBD–1.52, KPAR = 0.54 HSW–0.65 and KPAR = 0.53 HSB–0.92 were developed for the corresponding relationships. The parameters of these models are not significantly different from those of models developed for Punta Banda Estuary, another Baja California lagoon, with the exception of the one for the KPAR-HSW relationship. Also, parameters of the KPAR-ZSD model for San Quintín Bay and Punta Banda Estuary are not significantly different from those developed for coastal waters near Santa Barbara, California. A set of general models is proposed that may apply to coastal water bodies of northwestern Baja California and southern California (KPAR = 1.45 ZSD –1.10, KPAR = 0.92 ZBD–1.45, and KPAR = 0.70 HSB –1.10). While this approach may be universal, more data are needed to explore the variability of the parameters between different water bodies.
Immunomodulatory response of superoxide dismutase in juvenile American white shrimp (Litopenaeus vannamei) exposed to immunostimulants
Authors: Campa-Córdova AI , Hernández-Saavedra NY , Aguirre-Guzmán G , Ascencio F
Published: August 2017

Immunomodulatory action of manganese superoxide dismutase (Mn-SOD) in juvenile American white shrimp (Litopenaeus vannamei) was studied. Shrimp between 0.7 and 1.0 g were immersed in aerated β-glucan, lipopolysaccharide (LPS), fucoidan, and heat-killed Vibrio penaeicida solutions for 6 h. The enzymatic activity of Mn-SOD in entire organisms was investigated to evaluate whether different immunostimulants were able to induce antioxidant activity. The immunostimulants tested activated the immune system in juvenile shrimp and the highest antioxidant response was observed 48 h after the challenge with β-glucan, LPS, fucoidan and heat-killed V. penaeicida. The bacterin caused 3.2 times more Mn-SOD activity than the control group. Immunostimulated shrimp were challenged with live V. penaeicida on the tenth day and a second antioxidant response was observed 48 h after exposure to live pathogenic bacteria. Immunostimulated shrimp with β-glucan showed the highest Mn-SOD response (2.5 times more than the control group). This study showed the capacity of juvenile shrimp to enhance antioxidant response during a challenge with pathogenic bacteria after exposure to immunostimulants.
Mesoscale dynamics and yellowfin tuna catches in the Mexican Pacific
Authors: Torres-Orozco E , Trasviña A , Muhlia-Melo A , Ortega-García S
Published: August 2017

Catch data of the yellowfin tuna (YFT) fishery were used to study the relationship between the seasonal and spatial variations of YFT with or without the presence of mesoscale structures at the entrance to the Gulf of California (19º–24º N, 104º–112º W). The YFT catches were distributed mainly over the continental shelf and around islands and seamounts. High concentration sets of YFT occurred throughout the year around the Marías islands and Cabo Corrientes, particularly in March and June. A warm (>28ºC) coastal jet with a width of 1.5 Rossby radius (~20.6 km) was observed off Cabo Corrientes during February and April, covering all the continental shelf off Cabo Corrientes. The jet moved at an average speed of 0.31 m s–1 and extended northwards to the Roca Corbetera seamount. The interaction with cooler water generated a frontal zone around which the YFT catches were concentrated. In contrast, during March the wind field was more favorable for the development of coastal upwelling off Cabo Corrientes. We observed an upwelling region with sea surface temperature of 18ºC and an offshore width of about a 3.7 Rossby radius of cold water that covered some 2600 km2. The YFT catches occurred in warmer water north of the upwelling zone.
Knowledge Mobilization and Mental Health Policy: Lessons from the Canadian Consensus Conference on the Mental Health of Emerging Adults
Authors: Mulvale Gillian , Roussakis Christina , Canning Christopher , Papadodoulos Despina , Knoops Francine
Published: August 2017

This case study explores how the Consensus Conference on the Mental Health of Emerging Adults, hosted by the Mental Health Commission of Canada in 2015, can impact mental health policy and practice in Canada. The study draws on interviews from 14 delegates who attended the conference. Participants praised innovations such as the inclusion of an emerging adult panel that provided feedback on all discussions, and efforts to make the consensus-building process meaningful in the Canadian policy context. Findings suggest that consensus conferences are a promising way to operationalize the Mental Health Strategy for Canada through policy and practice changes.
Impact of volcanic aerosols on stratospheric ozone recovery
Authors: Naik Vaishali , Horowitz Larry W. , Daniel Schwarzkopf M. , Lin Meiyun
Published: August 2017

We use transient GFDL‐CM3 chemistry‐climate model simulations over the 2006–2100 period to show how the influence of volcanic aerosols on the extent and timing of ozone recovery varies with (a) future greenhouse gas scenarios (Representative Concentration Pathway (RCP)4.5 and RCP8.5) and (b) halogen loading. Current understanding is that elevated volcanic aerosols reduce ozone under high halogen loading but increase ozone under low halogen loading when the chemistry is more NOx dominated. With extremely low aerosol loadings (designated here as “background”), global stratospheric ozone burden is simulated to return to 1980 levels around 2050 in the RCP8.5 scenario but remains below 1980 levels throughout the 21st century in the RCP4.5 scenario. In contrast, with elevated volcanic aerosols, ozone column recovers more quickly to 1980 levels, with recovery dates ranging from the mid‐2040s in RCP8.5 to the mid‐2050s to early 2070s in RCP4.5. The ozone response in both future emission scenarios increases with enhanced volcanic aerosols. By 2100, the 1980 baseline‐adjusted global stratospheric ozone column is projected to be 20–40% greater in RCP8.5 and 110–200% greater in RCP4.5 with elevated volcanic aerosols compared to simulations with the extremely low background aerosols. The weaker ozone enhancement at 2100 in RCP8.5 than in RCP4.5 in response to elevated volcanic aerosols is due to a factor of 2.5 greater methane in RCP8.5 compared with RCP4.5. Our results demonstrate the substantial uncertainties in stratospheric ozone projections and expected recovery dates induced by volcanic aerosol perturbations that need to be considered in future model ozone projections.
Analyses of electron runaway in front of the negative streamer channel
Authors: Babich L. P. , Bochkov E. I. , Kutsyk I. M. , Neubert T. , Chanrion O.
Published: August 2017

X‐ray and γ‐ray emissions, observed in correlation with negative leaders of lightning and long sparks of high‐voltage laboratory experiments, are conventionally connected with the bremsstrahlung of high‐energy runaway electrons (REs). Here we extend a focusing mechanism, analyzed in our previous paper, which allows the electric field to reach magnitudes, required for a generation of significant RE fluxes and associated bremsstrahlung, when the ionization wave propagates in a narrow, ionized channel created by a previous streamer. Under such conditions we compute the production rate of REs per unit streamer length as a function of the streamer velocity and predict that, once a streamer is formed with the electric field capable of producing REs ahead of the streamer front, the ionization induced by the REs is capable of creating an ionized channel that allows for self‐sustained propagation of the RE‐emitting ionization wave independent of the initial electron concentration. Thus, the streamer coronas of the leaders are probable sources of REs producing the observed high‐energy radiation. To prove these predictions, new simulations are planned, which would show explicitly that the preionization in front of the channel via REs will lead to the ionization wave propagation self‐consistent with RE generation.
Observing System Simulation Experiments for an array of autonomous biogeochemical profiling floats in the Southern Ocean
Authors: Kamenkovich Igor , Haza Angelique , Gray Alison R. , Dufour Carolina O. , Garraffo Zulema
Published: August 2017

This study uses Observing System Simulation Experiments (OSSEs) to examine the reconstruction of biogeochemical variables in the Southern Ocean from an array of autonomous profiling floats. In these OSSEs, designed to be relevant to the Southern Ocean Carbon and Climate Observation and Modeling (SOCCOM) project, the simulated floats move with oceanic currents and sample dissolved oxygen and inorganic carbon. The annual mean and seasonal cycle of these fields are then reconstructed and compared to the original model fields. The reconstruction skill is quantified with the reconstruction error (RErr), defined as the difference between the reconstructed and actual model fields, weighted by a local measure of the spatiotemporal variability. The square of the RErr is small (<0.5) for 150 floats in most of the domain, which is interpreted to mean that the reconstruction skill is high. An idealized analytical study demonstrates that the RErr depends on the magnitude of the seasonal cycle, spatial gradients, speed of float movement, amplitude of mesoscale variability, and number of floats. These factors explain a large part of the spatial variability in the RErr and can be used to predict the reconstruction skill of the SOCCOM array. Furthermore, our results demonstrate that an array size of 150 floats is a reasonable choice for reconstruction of surface properties and annual‐mean 2000 m inventories, with the exception of the seasonal cycle in parts of the Indo‐Atlantic, and that doubling this number to 300 results in a very modest increase in the reconstruction skill for dissolved oxygen.
Characterizing the chaotic nature of ocean ventilation
Authors: MacGilchrist Graeme A. , Marshall David P. , Johnson Helen L. , Lique Camille , Thomas Matthew
Published: August 2017

Ventilation of the upper ocean plays an important role in climate variability on interannual to decadal timescales by influencing the exchange of heat and carbon dioxide between the atmosphere and ocean. The turbulent nature of ocean circulation, manifest in a vigorous mesoscale eddy field, means that pathways of ventilation, once thought to be quasi‐laminar, are in fact highly chaotic. We characterize the chaotic nature of ventilation pathways according to a nondimensional “filamentation number,” which estimates the reduction in filament width of a ventilated fluid parcel due to mesoscale strain. In the subtropical North Atlantic of an eddy‐permitting ocean model, the filamentation number is large everywhere across three upper ocean density surfaces—implying highly chaotic ventilation pathways—and increases with depth. By mapping surface ocean properties onto these density surfaces, we directly resolve the highly filamented structure and confirm that the filamentation number captures its spatial variability. These results have implications for the spreading of atmospherically‐derived tracers into the ocean interior.
Spatiotemporal changes in extreme sea levels along the coasts of the North Atlantic and the Gulf of Mexico
Authors: Marcos Marta , Woodworth Philip L.
Published: August 2017

Extreme sea levels along the densely monitored coasts of the North Atlantic Ocean and the Gulf of Mexico have been investigated using high‐frequency tide gauge measurements in the GESLA‐2 data set (www.gesla.org). Our results, based on nontidal residuals and skew surges in records since 1960, confirm that mean sea level (MSL) is a major, but not a unique, driver of extremes. Regionally coherent linear trends and correlations with large‐scale climate patterns are found in extreme events, even after the removal of MSL. A similar conclusion, that MSL is a major but not the only driver of extremes, comes from a small number of long records starting in the mid‐19th century. The records show slight increases in the intensity of extreme episodes at centennial time scales, together with multidecadal variability unrelated to MSL. Objective statistical criteria have been used to investigate whether extreme sea level distributions are stationary or not, resulting in nonstationarity being favored in many records, with or without accounting for changes in MSL. Extremes have been found to favor a non‐Gumbel behavior at many locations, with implications for the accuracy of return levels for coastal engineering.
Evaluation and analysis of AMSR‐2, SMOS, and SMAP soil moisture products in the Genhe area of China
Authors: Cui Huizhen , Jiang Lingmei , Du Jinyang , Zhao Shaojie , Wang Gongxue , Lu Zheng , Wang Jian
Published: August 2017

High‐precision soil moisture products play an important role in estimating forest carbon storage and carbon emissions in Genhe, China. In this paper, we evaluated the Soil Moisture and Ocean Salinity (SMOS) L3 product, the Soil Moisture Active Passive (SMAP) L3 product, and four soil moisture products derived from the Advanced Microwave Scanning Radiometer 2 (AMSR‐2), i.e., the Dual Channel Algorithm based on the Qp model (QDCA) product, the Japan Aerospace Exploration Agency (JAXA) L3 product, and the Land Parameter Retrieval Model (LPRM) C band and X band products in the Genhe area of China. The results indicated that the root‐mean‐square error (RMSE) and bias of the QDCA product were lower than those of the other AMSR‐2 products, although the QDCA still fell outside of the acceptable range with a volumetric error of no greater than 6%. The JAXA product underestimated the soil moisture and had a constant bias of 0.089–0.099 m3 m−3. The LPRM C‐band and X‐band products had a constant variable season bias of 0.261–0.576 m3 m−3. The quality of the SMOS was better than that of the AMSR‐2 products; however, the results were noisy and unstable. The SMAP was closest to the ground measurements and presented a low RMSE (0.039–0.063 m3 m−3) and bias (0.022–0.050 m3 m−3). Finally, an assessment was performed on the parameters in these soil moisture algorithms.
The characteristics of the lower stratospheric gravity wavefield above Halley (75°S, 26°W), Antarctica, from radiosonde observations
Authors: Moffat‐Griffin T. , Colwell S. R.
Published: August 2017

Daily radiosonde observations between 2003 and 2013 from Halley research station, Antarctica (75°S, 26°W), are used to determine climatologies of gravity wave properties in the lower stratosphere (between 15 km and 22 km altitude). Individual waves are extracted from the radiosonde profile using wavelet analysis and separated into upward and downward propagating waves. An increase in the percentage of downward propagating waves (~30% of the waves) is seen during the winter months. For the upward and downward propagating waves, their horizontal and vertical wavelength, intrinsic frequency, energy density, pseudomomentum flux, and direction of propagation are determined. The upward propagating wavefield is found to be dominated by waves with short vertical wavelength (~1 km) and low intrinsic frequency (ω ~ f). The downward propagating wavefield is composed of a wider distribution of vertical wavelength waves and has a larger proportion of higher‐frequency waves present. The upward propagating waves show an increase in total energy density in autumn and spring; the larger increase occurs during spring (up to 1.7 J kg−1 in September). The downward propagating waves increase in total energy density occurs during wintertime (up to 0.7 J kg−1 in June). During winter the contributions of the upward and downward propagating waves to the total energy density and pseudomomentum flux are almost equal. This paper details the first study of individual gravity wave properties combined into upward and downward propagating wave climatologies in the lower stratosphere above Halley.
Aromatic Halogenation
Authors: Larock Richard C. , Zhang Li
Published: August 2017

This article has no abstract.
Hydrophobic, Flexible, and Lightweight MXene Foams for High‐Performance Electromagnetic‐Interference Shielding
Authors: Liu Ji , Zhang Hao‐Bin , Sun Renhui , Liu Yafeng , Liu Zhangshuo , Zhou Aiguo , Yu Zhong‐Zhen
Published: August 2017

Ultrathin, lightweight, and flexible electromagnetic‐interference (EMI) shielding materials are urgently required to manage increasingly serious radiation pollution. 2D transition‐metal carbides (MXenes) are considered promising alternatives to graphene for providing excellent EMI‐shielding performance due to their outstanding metallic electrical conductivity. However, the hydrophilicity of MXene films may affect their stability and reliability when applied in moist or wet environments. Herein, for the first time, an efficient and facile approach is reported to fabricate freestanding, flexible, and hydrophobic MXene foam with reasonable strength by assembling MXene sheets into films followed by a hydrazine‐induced foaming process. In striking contrast to well‐known hydrophilic MXene materials, the MXene foams surprisingly exhibit hydrophobic surfaces and outstanding water resistance and durability. More interestingly, a much enhanced EMI‐shielding effectiveness of ≈70 dB is achieved for the lightweight MXene foam as compared to its unfoamed film counterpart (53 dB) due to the highly efficient wave attenuation in the favorable porous structure. Therefore, the hydrophobic, flexible, and lightweight MXene foam with an excellent EMI‐shielding performance is highly promising for applications in aerospace and portable and wearable smart electronics.
Metal‐Loaded Dielectric Resonator Metasurfaces for Radiative Cooling
Authors: Zou Chengjun , Ren Guanghui , Hossain Md Muntasir , Nirantar Shruti , Withayachumnankul Withawat , Ahmed Taimur , Bhaskaran Madhu , Sriram Sharath , Gu Min , Fumeaux Christophe
Published: August 2017

Tailoring emissivity and absorptivity of structured material surfaces to match atmospheric transmission spectral windows can lead to radiative cooling that consumes no external energy. Recent advances in nanofabrication technology have facilitated progress in the realization of structured metasurfaces. In particular, subwavelength dielectric resonator metasurface supporting various resonance modes can be efficient absorbers. Here, such metasurfaces are proposed and experimentally demonstrated enhanced by metal loading to obtain strong broadband thermal emission over a wide angle at mid‐infrared frequencies. This concept results in passive cooling devices that can lower temperature by 10 °C below ambient temperature. Importantly, the utilization of standard constituent materials and processes lead to scalable fabrication compatible with silicon photonics integration, which will enable effective and energy‐efficient applications in passive cooling and thermodynamic control.
Interfaces in Perovskite Solar Cells
Authors: Fakharuddin Azhar , Schmidt‐Mende Lukas , Garcia‐Belmonte Germà , Jose Rajan , Mora‐Sero Ivan
Published: August 2017

Rapid improvement in photoconversion efficiency (PCE) of solution processable organometallic hybrid halide based perovskite solar cells (PSCs) have taken the photovoltaic (PV) community with a surprise and has extended their application in other electronic devices such as light emitting diodes, photo detectors and batteries. Together with efforts to push the PCE of PSCs to record values >22% – now at par with that of crystalline silicon solar cells – origin of their PV action and underlying physical processes are also deeply investigated worldwide in diverse device configurations. A typical PSC consists of a perovskite film sandwiched between an electron and a hole selective contact thereby creating ESC/perovskite and perovskite/HSC interfaces, respectively. The selective contacts and their interfaces determine properties of perovskite layer and also control the performance, origin of PV action, open circuit voltage, device stability, and hysteresis in PSCs. Herein, we define ideal charge selective contacts, and provide an overview on how the choice of interfacing materials impacts charge accumulation, transport, transfer/recombination, band‐alignment, and electrical stability in PSCs. We then discuss device related considerations such as morphology of the selective contacts (planar or mesoporous), energetics and electrical properties (insulating and conducting), and its chemical properties (organic vs inorganic). Finally, the outlook highlights key challenges and future directions for a commercially viable perovskite based PV technology.
Selective α‐Oxyamination and Hydroxylation of Aliphatic Amides
Authors: Li Xinwei , Lin Fengguirong , Huang Kaimeng , Wei Jialiang , Li Xinyao , Wang Xiaoyang , Geng Xiaoyu , Jiao Ning
Published: August 2017

Compared to the α‐functionalization of aldehydes, ketones, even esters, the direct α‐modification of amides is still a challenge because of the low acidity of α‐CH groups. The α‐functionalization of N−H (primary and secondary) amides, containing both an unactived α‐C−H bond and a competitively active N−H bond, remains elusive. Shown herein is the general and efficient oxidative α‐oxyamination and hydroxylation of aliphatic amides including secondary N−H amides. This transition‐metal‐free chemistry with high chemoselectivity provides an efficient approach to α‐hydroxy amides. This oxidative protocol significantly enables the selective functionalization of inert α‐C−H bonds with the complete preservation of active N−H bond.
The Helix to Super‐Helix Transition in the Self‐Assembly of π‐Systems: Superseding of Molecular Chirality at Hierarchical Level
Authors: Hifsudheen Mohamed , Mishra Rakesh K. , Vedhanarayanan Balaraman , Praveen Vakayil K. , Ajayaghosh Ayyapanpillai
Published: August 2017

Higher‐order super‐helical structures derived from biological molecules are known to evolve through opposite coiling of the initial helical fibers, as seen in collagen protein. A similar phenomenon is observed in a π‐system self‐assembly of chiral oligo(phenyleneethylene) derivatives (S)‐1 and (R)‐1 that explains the unequal formation of both left‐ and right‐handed helices from molecule having a specific chiral center. Concentration‐ and temperature‐dependent circular dichroism (CD) and UV/Vis spectroscopic studies revealed that the initial formation of helical aggregates is in accordance with the molecular chirality. At the next level of hierarchical self‐assembly, coiling of the fibers occurs with opposite handedness, thereby superseding the command of the molecular chirality. This was confirmed by solvent‐dependent decoiling of super‐helical structures and concentration‐dependent morphological analysis.
β‐Functionalized Push–Pull opp‐Dibenzoporphyrins as Sensitizers for Dye‐Sensitized Solar Cells
Authors: Hu Yi , Yellappa Shivaraj , Thomas Michael B. , Jinadasa R. G. Waruna , Matus Alex , Shulman Max , D'Souza Francis , Wang Hong
Published: August 2017

A novel class of β‐functionalized push–pull zinc opp‐dibenzoporphyrins were designed, synthesized, and utilized as sensitizers for dye‐sensitized solar cells. Spectral, electrochemical, and computational studies were systematically performed to evaluate their spectral coverage, redox behavior, and electronic structures. These porphyrins displayed much broader spectral coverage and more facile oxidation upon extension of the π conjugation. Free‐energy calculations and femtosecond transient absorption studies (charge injection rate in the range of 1011 s−1) suggested efficient charge injection from the excited singlet state of the porphyrin to the conduction band of TiO2. The power conversion efficiency (η) of YH3 bearing acrylic acid linkers (η=5.9 %) was close to that of the best ruthenium dye N719 (η=7.4 %) under similar conditions. The superior photovoltaic performance of YH3 was attributed to its higher light‐harvesting ability and more favorable electron injection and collection, as supported by electrochemical impedance spectral studies. This work demonstrates the exceptional potential of benzoporphyrins as sensitizers for dye‐sensitized solar cells.
Thermal mapping on male genital and skin tissues of laptop thermal sources and electromagnetic interaction
Authors: Safari Mahdi , Mosleminiya Navid , Abdolali Ali
Published: August 2017

Since the development of communication devices and expansion of their applications, there have been concerns about their harmful health effects. The main aim of this study was to investigate laptop thermal effects caused by exposure to electromagnetic fields and thermal sources simultaneously; propose a nondestructive, replicable process that is less expensive than clinical measurements; and to study the effects of positioning any new device near the human body in steady state conditions to ensure safety by U.S. and European standard thresholds. A computer simulation was designed to obtain laptop heat flux from SolidWorks flow simulation. Increase in body temperature due to heat flux was calculated, and antenna radiation was calculated using Computer Simulation Technology (CST) Microwave Studio software. Steady state temperature and specific absorption rate (SAR) distribution in user's body, and heat flux beneath the laptop, were obtained from simulations. The laptop in its high performance mode caused 420 (W/m2) peak two‐dimensional heat flux beneath it. The cumulative effect of laptop in high performance mode and 1 W antenna radiation resulted in temperatures of 42.9, 38.1, and 37.2 °C in lap skin, scrotum, and testis, that is, 5.6, 2.1, and 1.4 °C increase in temperature, respectively. Also, 1 W antenna radiation caused 0.37 × 10−3 and 0.13 × 10−1 (W/kg) peak three‐dimensional SAR at 2.4 and 5 GHz, respectively, which could be ignored in reference to standards and temperature rise due to laptop use. Bioelectromagnetics. 38:550–558, 2017. © 2017 Wiley Periodicals, Inc.
Pyrolysis of sugarcane bagasse in a fixed bed reactor: Influence of operational conditions in the distribution of products
Authors: Gonçalves Edvan Vinícius , Teodoro Carlos , Seixas Fernanda Lini , Canesin Edmilson Antonio , Olsen Scaliante Mara Heloisa Neves , Gimenes Marcelino Luis , De Souza Marcos
Published: August 2017

This work experimentally evaluated the pyrolysis of sugarcane bagasse in a fixed bed reactor in order to obtain products useful in energy applications. The raw material was characterized to understand its behaviour during the thermal degradation process. The effects of operating conditions on mass yields of bio‐oil, biochar, and non‐condensable gases were investigated. The operating variables studied were temperature (400 to 700 °C), particle size (<0.5 mm, 0.5–1.0 mm, and 1.0–1.41 mm), heating rate (5, 10, and 15 °C/min), and nitrogen flow (50, 100, and 200 mL/min). Analysis of variance showed that for almost all product mass yields, with the exception of the effect of nitrogen flow in bio‐oil yield, the treatment levels result in different means. The highest bio‐oil yield (0.54 g/g) occurred at 600 °C, at a heating rate of 15 °C/min, at a flow rate of 200 mL/min, and for a particle size of 0.5 to 1.0 mm. The process temperature and particle size were the most influential factors in the results.
Atrial fibrillation variability on long‐term monitoring of implantable cardiac rhythm management devices
Authors: Kaplan Rachel M. , Ziegler Paul D. , Koehler Jodi , Glotzer Taya V. , Passman Rod S.
Published: August 2017

Background

Atrial fibrillation (AF) burden and duration are predictors of thromboembolic events. The random nature of these measures may affect clinical decision making. The objective of this study was to determine temporal changes in AF burden as detected by continuous monitoring.

Hypothesis

AF burden changes over time when detected by continuous monitoring.

Methods

A post hoc analysis of patients enrolled in the TRENDS (A Prospective Study of the Clinical Significance of Atrial Arrhythmias Detected by Implanted Device Diagnostics) study with ≥1 stroke risk factor(s) who were implanted with a dual‐chamber cardiac rhythm management device (CRMD) and had AF burden data available for ≥2 years was performed. AF burden was defined as no AF, low AF (<5.5 hours on any given day), or high AF burden (≥5.5 hours in a day), and was first assessed over the initial 30 days following enrollment and then reassessed at 6‐month intervals for 2 years.

Results

Among 394 patients included, the average age was 70.2 ± 10.9 years, 71% were male, and mean CHA2DS2‐VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or TIA, vascular disease, age 65–74 years, sex category) score was 3.7 ± 1.6. In the 30‐day baseline period, 75.1% of patients had no AF, 11.2% had low AF, and 13.7% had high AF. Over the subsequent 2 years, 40.0% of patients initially classified as no AF or low AF experienced periods with high AF, whereas 59.3% of patients initially classified as high AF experienced ≥6 consecutive months with no AF or low AF. Advanced age was the sole predictor of AF progression.

Conclusions

Significant temporal variability in AF burden exists when measured continuously with an implantable CRMD.
Generating and Maintaining Transgenic Cryptosporidium parvum Parasites
Authors: Pawlowic Mattie C. , Vinayak Sumiti , Sateriale Adam , Brooks Carrie F. , Striepen Boris
Published: August 2017

The apicomplexan parasite Cryptosporidium is a leading cause of diarrheal disease and an important contributor to overall global child mortality. We currently lack effective treatment and immune prophylaxis. Recent advances now permit genetic modification of this important pathogen. We expect this to produce rapid advances in fundamental as well as translational research on cryptosporidiosis. Here we outline genetic engineering for Cryptosporidium in sufficient detail to establish transfection in any laboratory that requires access to this key technology. This chapter details the conceptual design consideration, as well as the experimental steps required to transfect, select, and isolate transgenic parasites. We also provide detail on key in vitro and in vivo assays to detect, validate, and quantify genetically modified Cryptosporidium parasites. © 2017 by John Wiley & Sons, Inc.
Tree seed traits’ response to monsoon climate and altitude in Indian subcontinent with particular reference to the Himalayas
Authors: Singh Surendra P. , Phartyal Shyam S. , Rosbakh Sergey
Published: August 2017

Seed traits are related to several ecological attributes of a plant species, including its distribution. While the storage physiology of desiccation‐sensitive seeds has drawn considerable attention, their ecology has remained sidelined, particularly how the strong seasonality of precipitation in monsoonal climate affects their temporal and spatial distribution. We compiled data on seed mass, seed desiccation behavior, seed shedding, and germination periodicity in relation to monsoon and altitude for 198 native tree species of Indian Himalayas and adjoining plains to find out (1) the adaptive significance of seed mass and seed desiccation behavior in relation to monsoon and (2) the pattern of change in seed mass in relation to altitude, habitat moisture, and succession. The tree species fall into three categories with respect to seed shedding and germination periodicities: (1) species in which both seed shedding and germination are synchronized with monsoon, referred to as monsoon‐synchronized (MS, 46 species); (2) species in which seed germination is synchronized with monsoon, but seeds are shed several months before monsoon, referred to as partially monsoon‐synchronized (PMS, 112 species); and (3) species in which both shedding and germination occur outside of monsoon months, referred to as monsoon‐desynchronized (MD, 39 species). The seed mass ofMSspecies (1,718 mg/seed) was greater than that ofPMS(627 mg/seed) andMD(1,144 mg/seed). Of the 40 species with desiccation‐sensitive seeds, 45% belong to theMScategory, almost similar (approx. 47%) to woody plants with desiccation‐sensitive seeds in evergreen rain forests. Seed mass differed significantly as per seed desiccation behavior and successional stage. No relationship of seed mass was found with altitude alone and on the basis of seed desiccation behavior. However, seed mass trend along the altitude differed among monsoon synchronization strategies. Based on our findings, we conclude that in the predicted climate change (warming and uncertain precipitation pattern) scenario, a delay or prolonged break‐spell of monsoon may adversely affect the regeneration ecology of desiccation‐sensitive seed‐bearing species dominant over large forest areas of monsoonal climate.
Results of a national multicenter audit assessment of gynecologic history in surgical patients
Authors: Wilson Michael S.J. , Powell‐Bowns Matilda , Robertson Andrew G. , Luhmann Andreas , Richards Colin H. ,   the Scottish Surgical Research Group
Published: August 2017

Objective

To determine the adequacy of assessing gynecologic history for females of reproductive age (FRA) admitted to a general surgery department.

Methods

The present prospective multicenter audit included FRA who were admitted for elective or emergency procedures to general surgery departments in Scotland between May 11 and May 25, 2015. Data were compared between patients who were admitted for elective and emergency treatment.

Results

There were 530 FRA included from 18 centers, including 169 (31.9%) and 361 (68.1%) elective and emergency admissions, respectively. The date of last menstrual period was document for 203 (38.3%) patients, use of contraception for 149 (28.1%), sexual activity for 83 (15.7%), pregnancy status for 274 (51.7%), and the possibility of pregnancy for 237 (44.7%). A higher incidence of documented date of last menstrual period (P=0.002) and pregnancy status (P<0.001) were identified among emergency admissions, and the possibility of pregnancy was documented more commonly among elective admissions (P<0.001).

Conclusions

Key factors required for gynecologic assessment were often not documented for FRA admitted to general surgery both as elective and emergency admissions. Surgical teams and medical undergraduates require educating regarding the importance of obtaining gynecologic history for all FRA.
Protein adsorption in anion exchange resins – effects of polymer grafting, support structure porosity, and protein size
Authors: Zhu Mimi , Fuks Preston , Carta Giorgio
Published: August 2017

BACKGROUND

Anion exchange resins are used extensively for the purification of acidic proteins. Grafting charged polymers to a rigid porous structure has been shown to improve performance under varying conditions. Understanding the underlying mechanisms is important for the optimum design and selection of material properties and operating conditions.

RESULTS

Positively charged grafted polymers incorporated into a rigid, porous polymeric backbone structure are found to significantly enhance adsorption capacity and kinetics of the proteins bovine serum albumin (BSA, Mr ∼ 65 kDa) and thyroglobulin (Tg, Mr ∼ 660 kDa) but under different conditions. For the smaller BSA, binding increases with grafted polymer length and content and decreases with salt concentration. For the much larger Tg, binding increases with the addition of some salt for the polymer‐grafted resins but can be lower than that observed for ungrafted resins without added salt. This behavior is caused by diffusional hindrance due to the bound protein. Increasing the length of the grafted polymer or the pore size of the backbone improves the Tg adsorption kinetics.

CONCLUSION

Protein adsorption is controlled by different mechanisms dependent on polymer grafting, backbone structure, and size of the adsorbed protein. Optimum selection of resin properties and conditions is needed to maximize adsorption capacity and mass transfer kinetics. © 2017 Society of Chemical Industry
Revisiting thermoplastic polyurethane, from composition to morphology and properties
Authors: Solouki Bonab Vahab , Manas‐Zloczower Ica
Published: August 2017

Thermoplastic polyurethanes (TPUs) are among the most versatile engineering polymers. The presence of hard and soft segments on their backbone and specific hydrogen bond interactions between the hard segments, provide TPUs with outstanding engineering properties while rendering them as very complex systems to study. Knowledge of morphology–property relationship is essential for TPUs since their thermal and mechanical behavior are directly dictated by their complicated morphology. In this research, TPU morphological features related to the hard segment content (HSC) were explored in tandem with system macroscopic properties. It was observed that TPUs display multiscale phase separated morphology with specific morphological features dependent on the HSC. At a certain critical HSC, an interconnected network of hard segments was formed which resulted in significant changes in TPU properties. This was explained in analogy with percolation phenomena in filler reinforced systems and considering the hard segments as reinforcing agent. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1553–1564
Protein structure prediction: making AWSEM AWSEM‐ER by adding evolutionary restraints
Authors: Sirovetz Brian J. , Schafer Nicholas P. , Wolynes Peter G.
Published: August 2017

Protein sequences have evolved to fold into functional structures, resulting in families of diverse protein sequences that all share the same overall fold. One can harness protein family sequence data to infer likely contacts between pairs of residues. In the current study, we combine this kind of inference from coevolutionary information with a coarse‐grained protein force field ordinarily used with single sequence input, the Associative memory, Water mediated, Structure and Energy Model (AWSEM), to achieve improved structure prediction. The resulting Associative memory, Water mediated, Structure and Energy Model with Evolutionary Restraints (AWSEM‐ER) yields a significant improvement in the quality of protein structure prediction over the single sequence prediction from AWSEM when a sufficiently large number of homologous sequences are available. Free energy landscape analysis shows that the addition of the evolutionary term shifts the free energy minimum to more native‐like structures, which explains the improvement in the quality of structures when performing predictions using simulated annealing. Simulations using AWSEM without coevolutionary information have proved useful in elucidating not only protein folding behavior, but also mechanisms of protein function. The success of AWSEM‐ER in de novo structure prediction suggests that the enhanced model opens the door to functional studies of proteins even when no experimentally solved structures are available.
Temperature‐Triggered Sulfur Vacancy Evolution in Monolayer MoS2/Graphene Heterostructures
Authors: Liu Mengxi , Shi Jianping , Li Yuanchang , Zhou Xiebo , Ma Donglin , Qi Yue , Zhang Yanfeng , Liu Zhongfan
Published: August 2017

The existence of defects in 2D semiconductors has been predicted to generate unique physical properties and markedly influence their electronic and optoelectronic properties. In this work, it is found that the monolayer MoS2 prepared by chemical vapor deposition is nearly defect‐free after annealing under ultrahigh vacuum conditions at ≈400 K, as evidenced by scanning tunneling microscopy observations. However, after thermal annealing process at ≈900 K, the existence of dominant single sulfur vacancies and relatively rare vacancy chains (2S, 3S, and 4S) is convinced in monolayer MoS2 as‐grown on Au foils. Of particular significance is the revelation that the versatile vacancies can modulate the band structure of the monolayer MoS2, leading to a decrease of the bandgap and an obvious n‐doping effect. These results are confirmed by scanning tunneling spectroscopy data as well as first‐principles theoretical simulations of the related morphologies and the electronic properties of the various defect types. Briefly, this work should pave a novel route for defect engineering and hence the electronic property modulation of three‐atom‐thin 2D layered semiconductors.
The Impact of Federal Homelessness Funding on Homelessness
Authors: Lucas David S.
Published: August 2017

Federal spending on homelessness has increased significantly in recent years. I estimate the relationship between federal homelessness funding and homeless counts in 2011, 2013, and 2015 cross sections. I instrument for funding using a community's pre‐1940 housing share, a key variable in an originally unrelated funding formula borrowed for homelessness grants. Funding increases sheltered homelessness; meanwhile, funding is unrelated to unsheltered homelessness. Lower bound estimates suggest that the minimum cost of reducing unsheltered homelessness has increased over time, from $16,400 in 2011 to $20,800 in 2013 to $50,000 in 2015. In 2013, an additional $1 thousand dollars corresponds to a .309 higher homeless rate per 10,000 people. The effect is larger for families than individuals. Funding is positively related to chronic homelessness and is unrelated to youth and child homelessness. My results suggest limitations on federal funding's ability to reduce homelessness among some of the most marginalized groups in society.
New perspectives on the neurophysiology of primate amygdala emerging from the study of naturalistic social behaviors
Authors: Gothard Katalin M. , Mosher Clayton P. , Zimmerman Prisca E. , Putnam Philip T. , Morrow Jeremiah K. , Fuglevand Andrew J.
Published: August 2017

A major challenge of primate neurophysiology, particularly in the domain of social neuroscience, is to adopt more natural behaviors without compromising the ability to relate patterns of neural activity to specific actions or sensory inputs. Traditional approaches have identified neural activity patterns in the amygdala in response to simplified versions of social stimuli such as static images of faces. As a departure from this reduced approach, single images of faces were replaced with arrays of images or videos of conspecifics. These stimuli elicited more natural behaviors and new types of neural responses: (1) attention‐gated responses to faces, (2) selective responses to eye contact, and (3) selective responses to touch and somatosensory feedback during the production of facial expressions. An additional advance toward more natural social behaviors in the laboratory was the implementation of dyadic social interactions. Under these conditions, neurons encoded similarly rewards that monkeys delivered to self and to their social partner. These findings reinforce the value of bringing natural, ethologically valid, behavioral tasks under neurophysiological scrutiny. WIREs Cogn Sci 2018, 9:e1449. doi: 10.1002/wcs.1449

This article is categorized under:

Psychology > Emotion and Motivation

Neuroscience > Cognition

Neuroscience > Physiology