Minor Peak Research Articles

Using LiDAR waveform metrics to describe and identify successional stages of tropical dry forests

During the past several decades, full-waveform LiDAR has been widely employed to estimate biophysical and biochemical attributes of forests. Many LiDAR metrics have been proposed for distinguishing tree species. However, little work has been dedicated to identifying tools for accurately classifying forests in different levels of ecological succession. This paper explores the potential of full-waveform LiDAR metrics in the identification and classification of tropical dry forests (TDFs) at three levels of ecological succession: early, intermediate, and late. Based on the effective LiDAR waveform and the cumulative return energy curve from the Laser Vegetation Imaging Sensor (LVIS), we derived a total of 21 LiDAR metrics which can be classified into point-, line-, area-, or shape-based groups. We further evaluated their ability in differentiating TDF succession using multiple comparison analysis (Duncan method and Tamhane’s T2 method) and ISODATA clustering. Our results showed that the response of LiDAR energy could well reflect the variation in TDF vertical structure. The effective LiDAR waveform of the early successional stage was characterized by one narrow peak; the late successional stage was characterized by multiple major and minor peaks; and the intermediate stage showed transitional characteristics. The normalized cumulative curves tended to be linear with the development of succession. Our multiple comparison analysis suggested that shape- and area-based metrics were generally better than point- and line-based ones in the differentiation of successional stages. Meanwhile the late successional stage can be identified by metrics from any of the four metric groups, the early and intermediate successional stages can be better identified using shape- or area-based metrics. Our ISODATA classification results further confirmed the advantages of area-based metrics since they presented the highest accuracies in nearly all accuracy measurements and for all successional stages. Our study suggests the encouraging potential of LiDAR waveform metrics in the quantification of tropical forests structure as a function of different levels of ecological succession.

Optimal set of electrode potential enhances the toxicity response of biocathode to formaldehyde

The autotrophic biocathode was promising as a broad spectrum, rapid-responding and sensitive sensing element for the early warning of toxicants in water. However, we found that the baseline current and the responsivity strongly relied on the cathode potential. Here we poised cathode potentials at 0, −0.2 and −0.4 V to investigate the effect of electrode potential on the sensor responsivity. With formaldehyde as the tested toxicant, the biocathode poised at −0.2 V had the highest baseline current (118.2 ± 10.7 A m−2) and the lowest toxicity response concentration (0.00148%), which exhibited a 6–64 times higher response ratio (1.4 × 104 A%−1 m−3) than those controlled at 0 V (2.3 × 103 A%−1 m−3) and −0.4 V (2.2 × 102 A%−1 m−3). First derivative of cyclic voltammetries revealed that the biocathode acclimated at −0.2 V had a highest main peak centered at 0.301 ± 0.006 V and several minor peaks between −0.2 to 0.2 V. Bacterial community analysis showed that Proteobacteria and Bacteroidetes families closely related to the sensing performance. Interestingly, Nitrospirae was obviously acclimated at −0.2 V, indicating that bacteria belonging to this phylum possibly contributed to the highest responsivity as well. Our findings revealed that the optimal set of electrode potential was critical to promote the toxicity responses of biocathode to the formaldehyde, and the differences were mainly from the microbial communities selected by different cathode potentials.

An acute gastroenteritis outbreak associated with person-to-person transmission in a primary school in Shanghai: first report of a GI.5 norovirus outbreak in China

BackgroundGII noroviruses are a common cause of acute gastroenteritis (AGE) outbreaks in institutional settings globally. However, AGE outbreaks caused by GI norovirus, especially the GI.5 genotype, are relatively uncommon.MethodsIn February 2017, an AGE outbreak occurred in a primary school in Shanghai, China. An outbreak investigation was undertaken, and fecal specimens, rectal swabs, and environmental swabs were collected. Pathogen detection was performed and the positive specimens were characterized by gene sequencing.ResultsThe descriptive epidemiological analysis suggested that this outbreak, involving 19 cases in two classes (designated classes A and B), was a small-scale propagated epidemic and person-to-person transmission was the most plausible transmission mode. The outbreak comprised two peaks, with 15 cases occurring in class A during the main peak and four cases occurring in class B in the subsequent minor peak. The primary attack rate was 38% and the secondary attack rate was 10%. Univariable logistic regression indicated that contacting a suspect case was a risk factor for norovirus infection, with an unadjusted OR of 5.6 (95% CI: 1.6–20.1). Six fecal specimens were positive for GI norovirus, with a single genotype, GI.5 norovirus, being involved, as characterized by genotyping. This outbreak was the first reported outbreak of GI.5 norovirus in China.ConclusionsThis study implies that GI.5 norovirus is a potential agent of outbreaks spread by person-to-person transmission in institutional settings. The investigation highlights the importance of sensitive surveillance, timely isolation of individuals who are ill, adequate hand hygiene, and proper environmental disinfection for prevention and control of AGE outbreaks caused by norovirus.

Sedimentary polycyclic aromatic hydrocarbons record recent anthropogenic activities near high-elevation Lake Sayram, northwest China

Mountain lakes are sensitive to natural perturbations and human activities. Profiles of anthropogenic polycyclic aromatic hydrocarbons (PAHs) in lake sediments serve as a natural archive from which human impacts on lakes can be reconstructed. Two parallel sediment cores (34 cm long) were extracted from Lake Sayram in the Tianshan Mountains of arid northwest China and dated using 210Pb and 137Cs. PAHs in the sediments were used to infer the past ∼150 years of anthropogenic impact on the lake. Results showed that PAH concentrations in the lake sediments were generally low, but nevertheless reflect some human activity. Benzo(ghi)perylene (BghiP) and indeno(1, 2, 3-cd)pyrene (IcdP) are typical markers of vehicular traffic, so significant correlations between PAH (especially BghiP and IcdP) and metal concentrations suggest that PAHs in sediments are effective proxies for anthropogenic activities. Furthermore, constrained cluster analysis revealed that the vertical profile of PAHs was characterized by three periods that correspond to changes in human activities. Prior to the 1960s, low PAH concentrations in the sediments generally indicate that the lake was virtually unaffected by human impact. BghiP and IcdP concentrations, however, displayed a minor peak in the 1950s, possibly reflecting transport from a remote polluted region via prevailing westerly winds. From the 1960s through the 1990s, relatively high values of PAHs, especially high molecular weight (HMW) PAHs BghiP and IcdP, and heavy metal enrichment factors (EFs), were related to increasing anthropogenic activities. After the 1990s, maxima of PAHs, HMW PAHs, BghiP, IcdP, EFs, together with highest total phosphorus (TP) and total organic carbon (TOC) values, reflect intensive human-related impact on the lake. The coincidence of limnological changes and local socio-economic development suggest that sedimentary PAHs record recent anthropogenic impact on Lake Sayram.

A hydrodynamics-informed, radiation model for HESS J0632 + 057 from radio to gamma-rays

Relativistic hydrodynamical simulations of the eccentric gamma-ray binary HESS J0632$+$057, show that the energy of a putative pulsar wind should accumulate in the binary surroundings between periastron and apastron, being released by fast advection close to apastron. To assess whether this could lead to a maximum of the non-thermal emission before apastron, we derive simple prescriptions for the non-thermal energy content, the radiation efficiency, and the impact of energy losses on non-thermal particles, in the simulated hydrodynamical flow. These prescriptions are used to estimate the non-thermal emission in radio, X-rays, GeV, and TeV, from the shocked pulsar wind in a binary system simulated using a simplified 3-dimensional scheme for several orbital cycles. Lightcurves at different wavelengths are derived, together with synthetic radio images for different orbital phases. The dominant peak in the computed lightcurves is broad and appears close to, but before, apastron. This peak is followed by a quasi-plateau shape, and a minor peak only in gamma rays right after periastron. The radio maps show ejection of radio blobs before apastron in the periastron-apastron direction. The results show that a scenario with a highly eccentric high-mass binary hosting a young pulsar can explain the general phenomenology of HESS J0632$+$057: despite its simplicity, the adopted approach yields predictions that are robust at a semi-quantitative level and consistent with multiwavelength observations.

Influence of sintering atmosphere and thermobaric treatment (TBT) on dielectric behaviors of CaCu3Ti4O12 ceramics

Copper titanate (CaCu3Ti4O12, or CCTO) ceramics sintered in oxygen and vacuum at 1100°C for 12 h have been treated by thermobaric treatment (TBT) at 9 GPa and 1000°C for 10 min and then quenched in liquid nitrogen (LN2). Pure cubic body-centered perovskite-related structure was confirmed from XRD results. Besides, after TBT and quenching, additional minor peaks of TiO2 and Cu were indexed, as well as a little cell volume expansion. A little reduction of the grain size as well as fuzzy grain boundaries can be observed in FE-SEM after TBT. The dielectric constant ε' of CCTO ceramics sintered in oxygen (∼4600 @ 100 Hz) were a half of those treated by TBT and quenching (∼9600 @ 100 Hz), whereas the value decreased almost by an order of magnitude (from 105 to 104) after TBT and quenching for the samples sintered in vacuum. The complex impedance spectra at high temperature showed three semicircles so a three RC model was used to explain the different relaxation regions consisting of grain, grain boundary and domain boundary. Besides, two relaxation peaks appeared in the frequency dependence of the imaginary part of the electric modulus formalism M⁎ and the complex impedance Z⁎. Moreover, the contributions of grain boundaries can be figured out by the relaxation activation energy Ere (338–629 meV) and the conduction one Edc (396–823 meV) fitted by M⁎ and Z⁎ plots separately. As a result, the disorder and heterogeneity typical of grain boundaries should be responsible for the giant dielectric relaxation characteristics of CCTO ceramics, which can be affected by the sintering atmosphere as well as the extreme treating conditions.

New Approach to Estimate Tidal Climatology From Ground‐ and Space‐Based Observations

AbstractThis paper proposes a new approach to obtain seasonal variations of global tides for the horizontal winds in the mesosphere and lower thermosphere region, based on daily tides derived from the global coverage of the TIMED Doppler Interferometer (TIDI) and the local‐time coverage of a meteor radar chain. The daily variations of different mesosphere and lower thermosphere tides are obtained taking advantage of empirical tidal mode (ETM), which is first derived from Global Scale Wave Model using empirical orthogonal function analysis. ETM displays latitudinal and vertical features of each tidal component in a realistic background atmosphere with dissipation effects. After fitting the observations by ETM day by day, the monthly mean of daily fitted results is then used to describe tidal monthly features. Seasonal variations of three major tidal components were found: DW1 in both zonal and meridional winds usually has two maxima around equinoxes, DE3 in zonal winds achieves their maximum in September, while that in meridional winds becomes strongest in February and November. SW2 in zonal winds reaches largest amplitudes in May in the southern hemisphere, and meridional winds has minor peaks in February and November in the northern hemisphere. At last, we superpose each tidal component with the same frequency to reconstruct the global diurnal and semidiurnal tidal winds. Comparing them with both of TIDI 60‐day average winds and outputs of Global Scale Wave Model model, similar characteristics and magnitudes indicate their consistency and confirm the reliability and feasibility of this new approach.

Theoretical Analysis of Double Logistic Distributed Activation Energy Model for Thermal Decomposition Kinetics of Solid Fuels

The distributed activation energy model (DAEM) has been widely used to analyze the thermal decomposition of solid fuels such as lignocellulosic biomass and its components, coal, microalgae, oil shale, waste plastics, and polymer etc. The DAEM with a single distribution of activation energies cannot describe those reactions well since the thermal decomposition normally involves multiple sub-processes of various components. The double DAEM employs a double distribution to represent the activation energies. The Gaussian distribution is usually used to represent the activation energies. However, it is not sufficiently accurate for addressing the activation energies in the initial and final stages of the thermal decomposition reactions of solid fuels. Compared to the Gaussian distribution, the logistic distribution is slightly thicker at the curve tail and suits better to describe the activation energy distribution. In this work, a theoretical analysis of the double logistic DAEM for the thermal decomposition kinetics of solid fuels has been systematically investigated. After the derivation of the double logistic DAEM, its numerical calculation method and the physical meanings of the model parameters have been presented. Three typical types of simulated double logistic DAEM processes have been obtained according to the overlapped situation of two derivative conversion peaks, namely separated, overlapped and partially overlapped processes. It is found that, for the partially overlapped process, the form of the minor peak (overlapped peak or peak shoulder) depends on the values of the frequency factor and heating rate. Considering the simulated processes and related examples from literature, the double logistic DAEM has been remarked as a more reliable tool with abundant flexibility to explain the thermal decomposition of various solid fuels. More accurate results are expected if the double logistic DAEM is coupled with the computational fluid dynamics (CFD) simulation for those reactions mentioned above.

Cerebrospinal fluid neopterin and CXCL13 are suitable biomarkers for staging and detection of treatment failure in a non-human primate model of human African trypanosomiasis

Abstract Background Follow-up of treated human African trypanosomiasis (HAT) patients has been a routine practice for confirming cure and early detection of treatment failure. Objective The aim of this study was to verify suitability of neopterin and CXCL13 as disease stage biomarkers and monitors of treatment efficacy in a vervet monkey model of HAT. Methods Six monkeys were infected with Trypanosoma brucei. Late stage disease was induced by sub-curative treatment with diminazene aceturate (DA) from 28 days post-infection (dpi). Upon relapse, the animals were treated curatively with melarsoprol (Mel B) from 82 dpi. Blood and cerebrospinal fluid (CSF) samples were collected weekly and assessed for parasitosis, as well as tested for neopterin and CXCL13 by ELISA, for a period of 39 weeks. Results Neopterin concentrations in serum increased rapidly after infection in early disease (stage 1), peaking at 14 dpi. Levels then dropped rapidly to pre-infection levels by 35 dpi. In contrast, there was a marginal increase in CSF neopterin during early infection, with a minor peak at 21 dpi. Serum CXCL13 increased rapidly from 7 dpi, peaking at 28 dpi. Levels dropped upon sub-curative treatment with DA. CXCL13 concentrations in CSF also increased gradually in early stage disease and continued to rise after sub-curative treatment with DA. Curative treatment with Mel B resulted in its gradual decline, reaching pre-infection levels 105 days later. Conclusions CSF neopterin and CXCL13 peak levels coinciding with time of relapses demonstrates the potential of these biomarkers in staging and detecting treatment failure. Moreover, the rapid fall in CSF neopterin after curative treatment confirms its great potential for use in development of a test of cure.

Flow mechanism of affecting an axial flow compressor performance and stability with cross-blade slot casing treatments

The objective of this study is to evaluate the effect of cross-blade slot casing treatment on the stability and performance of an axial flow compressor rotor. The experimental and unsteady calculated results both show that cross-blade slot casing treatment can generate about 22% stall margin improvement, and the compressor peak efficiency is reduced by about 13%. The detailed flow-field analyses indicate that the sucked and injected flow caused by the slots of cross-blade slot casing treatment can restrain the rotor tip passage blockage, which is made by the low energy tip clearance leakage vortex. When cross-blade slot casing treatment is applied, not only the rotor wheel flange work becomes lower in most of the rotor blade span, but also the flow loss in the blade tip passage becomes fairly large due to the strong interaction between the mainstream and the injected flows made by the slots. As a result, the compressor total pressure ratio and efficiency for cross-blade slot casing treatment are reduced obviously. Three kinds of new cross-blade slot casing treatment were designed according to the previous successful experience and investigated in this paper. The numerical results show that the new three cross-blade slot casing treatments both generate about 54% stall margin improvement at the cost of minor peak efficiency. For one new cross-blade slot casing treatment (CSCT2), the compressor peak efficiency is reduced by about 0.3%. The low energy TLV, which is present for cross-blade slot casing treatment, is removed by the strong sucked flow made by CSCT2. Moreover, the interaction between the mainstream and the injected flows caused by CSCT2 becomes weak obviously, and the corresponding flow loss is reduced greatly. Hence, the compressor stability and performance with CSCT2 are higher than those with cross-blade slot casing treatment.

Shear/rotation competition during the roll-up of acoustically excited shear layers

Naturally developing and acoustically excited shear layers at the Reynolds numbers $Re_{\unicode[STIX]{x1D703}_{0}}=U\unicode[STIX]{x1D703}_{0}/\unicode[STIX]{x1D708}=85{-}945$ are studied using the hot-wire (HW) anemometry and particle image velocimetry (PIV), with a focus on the shear/rotation competition during the initial Kelvin–Helmholtz (KH) roll-up. Velocity spectra and the spatial linear stability (LST) analysis characterize the fundamental ($f_{n}$) and its subharmonic ($f_{n}/2$) mode interacting due to the vortex pairing. For $276\leqslant Re_{\unicode[STIX]{x1D703}_{0}}\leqslant 780$, the root-mean-square (r.m.s.) of the streamwise turbulence intensity shows a double-peaking phenomenon, i.e. major and minor peaks of the $u_{rms}$ coexist towards the high-speed (HS) and the low-speed (LS) sides, respectively. The single/double-peaked $u_{rms}$ profiles are found to be correlated with the scattered/organized distribution of the shear/rotation, demonstrating a transitioning character with the downstream distance, $Re_{\unicode[STIX]{x1D703}_{0}}$ and the upstream turbulence levels. The rotating vortex cores and the corresponding peripheral shear regions, demonstrate the phase reversal of the velocity fluctuations with respect to the HS and the LS sides. Excitation at $f_{n}$ increases the vortex count by 21 %, advances the location of the first KH roll-up and hence also the minor peak formation location. Due to the enhanced pairing at the $f_{n}/2$ forcing, the vortex count reduces by 23 %. Before merging into the downstream rotation core, the upstream vortex is shifted towards the HS side and the major peak is accordingly augmented. Actuation advances the transition to the nonlinear state, as well as the saturation of the amplification factor. The volumetric topologies of the shear/rotation loops tracked in consecutive phases during the period of the acoustic excitation, separate from the edge and grow in time–space due to the viscous diffusion. The shearing and rotating loops are found to be associated with the thinning (elongation) and expansion (accumulation) of the vorticity, respectively.

Geographical and temporal patterns of rabies post exposure prophylaxis (PEP) incidence in humans in the Mekong River Delta and Southeast Central Coast regions in Vietnam from 2005 to 2015.

BackgroundIn Vietnam, rabies has been a notifiable disease for more than 40 years. Over the last five years, on average, more than 350,000 people per year have been bitten by dogs and cats while more than 80 human deaths have been reported yearly. No studies have been conducted to evaluate the geographical and temporal patterns of rabies in humans in Vietnam. Therefore, the main objective of this study was to assess the geographical and temporal distributions of rabies post exposure prophylaxis (PEP) incidence in humans in Vietnam from 2005 to 2015.MethodsAverage incidence rabies (AIR) PEP rates for every 3 or 4 years (2005–2008, 2009–2012 and 2013–2015) were calculated to describe the spatial distribution of rabies PEP. Hotspot analysis was implemented to identify patterns of spatial significance using the Getis-Ord Gi statistic. For temporal pattern analysis, two regions [Mekong River Delta (MRD) and Southeast Central Coast (SCC)], with the highest incidence rates, and the seasonal-decomposition procedure based on loess (STL), were compared to assess their temporal patterns of rabies PEP.FindingsWe found hotspots in southern Vietnam and coldspots in northern Vietnam during the study period. Rabies cases were limited to specific areas. In addition, the hotspot analysis showed that new risk areas were identified in each period which were not observed in incidence rate maps. The seasonal plots showed seasonal patterns with a strong peak in February/July and a minor peak in October/December in the MRD region. However, in the SCC, a small peak was detected at the early part of each year and a strong peak in the middle of each year.ConclusionOur findings provide insight into understanding the geographical and seasonal patterns of rabies PEP in Vietnam. This study provides evidence to aid policy makers when making decisions and investing resources. Such information may also be utilized to raise public awareness to prevent rabies exposures and reduce unnecessary PEP.

A review of progress towards sub-national malaria elimination in Matabeleland South Province, Zimbabwe (2011\u20132015): a qualitative study

BackgroundMalaria remains a public health problem in Zimbabwe. However, malaria elimination has become a foreseeable prospect with Matabeleland South Province making significant gains towards halting local malaria transmission. This study reviews malaria elimination progress and challenges to date utilizing the World Health Organization’s Malaria Programme Review framework.ResultsBetween 2011 and 2015, malaria incidence was less than one case per 1000 population at risk in all districts save for Beitbridge and Gwanda. The majority of cases were from Beitbridge with local transmission in the same. Incidence declined in Bulilima (p = 0.01), Gwanda (p = 0.72) and Umzingwane (p = 0.44), increasing in Beitbridge (p = 0.35), Insiza (p = 0.79) and Mangwe (p = 0.60). Overall provincial incidence declined although this was not statistically significant. Malaria transmission was bimodal, with a major peak in April and a minor peak in October. A case based malaria surveillance system existed but was not real-time. Foci response guidelines were not domesticated. Artemisinin formed the backbone of case management regimens with primaquine for gametocyte clearance. Indoor residual spraying coverages were below the national target of 95% for rooms targeted for spraying.ConclusionMatabeleland South province has set precedence for targeting sub-national malaria elimination in Zimbabwe. This experience may prove useful for national scale up. There is need to improve surveillance, foci response and intensification of activities to halt residual malaria transmission in Beitbridge District.

A Clean, Mild, and Efficient Preparation of Aryl 14H-benzo[a,j]xanthene leuco-dye Derivatives Via Nanocatalytic MCM-41-SO3H Under Ultrasonic Irradiation in Aqueous Media.

The present study has developed an efficient and eco-friendly protocol for the synthesis of aryl-14-H-dibenzo[a,j] xanthenes through a one-pot condensation reaction of 2-naphthol and arylaldehydes in aqueous media using the nanocatalytic MCM-41-SO3H under ultrasonic illumination. Using SEM and XRD analyses, MCM-41-SO3H nanoparticles were characterized. Therefore, for high magnification, taking the SEM image, the mesoporous surface of MCM-41-SO3H nanoparticles coated with gold for 2 minutes was characterized. Moreover, at a scan rate of 0.02° (2θ)/sec, XRD analysis from 1.5° (2θ) to 10.0° (2θ) was performed. For our considered sample, some well-ordered XRD patterns with one main peak as well as three minor peaks equal to those of MCM-41 materials were observed. The suggested route demonstrates very promising properties like higher yields, decrease in the time of reaction (5-10 min), mild and straightforward conditions, low level of toxicity, and inclusion of a cost-efficient and ecofriendly catalyst having considerable reusability.

High temperature multidimensional gas chromatographic approach for improved separation of triacylglycerols in olive oil

Heart-cut multidimensional gas chromatographic (H/C MDGC) methods under suitable flow and high temperature (T) program conditions were developed to separate olive oil triacylglycerols (TAGs). Different column sets were selected for further evaluation, each with relatively short non-polar first dimension (1D) and mid-polar second dimension (2D) columns of high T limits (350 °C). The 1D separation displayed three major groups of peaks in an area ratio of approximately 5:33:62 (of increasing retention), using flame ionisation detection (FID). Four groups of minor peaks, with 2 of them located between the major peaks, were also detected. The H/C fractions of the minor peaks, and sub-sampled regions across the major peaks eluting from the 1D outlet, were cryotrapped at the 2D inlet. The trapped TAGs then underwent temperature programmed 2D separation. Each of the ‘H/C’ zones generally gave 2–5 – and in some cases more – separated peaks of TAGs on the 2D column, under suitable flow condition and phase polarity that resulted in improved separation. Six sub-sampled H/Cs from various regions of the individual peaks from the 1D column were simultaneously trapped and released to 2D, resulting in apparently more than 22 individual TAG peaks. According to their different retention times, different TAGs were revealed within each of the 3 major groups, using H/C sub-sampling. A comprehensive sampling strategy that covers most of the 1D peaks further revealed the presence of more TAGs in the olive oil sample. This tandem column strategy was able to resolve more components than that usually observed on a single column.

Phoenixin: a novel brain-gut-skin peptide with multiple bioactivity.

In this brief review we summarize the current fndings relative to the discovery of a small peptide ligand, phoenixin (PNX). Using a bioinformatic approach, two novel peptides PNX-14 and PNX-20 containing 14 and 20 amino acids, respectively, were isolated from diverse tissues including the brain, heart, lung and stomach. Mass spectrometry analysis identified a major and minor peak corresponding to PNX-14 and PNX-20, in rat or mouse spinal cord extracts. With the use of a rabbit polyclonal antiserum, phoenixin immunoreactivity (irPNX) was detected in discrete areas of the rodent brain including several hypothalamic subnuclei and dorsal motor nucleus of the vagus. In addition, irPNX was detected in a population of sensory ganglion cells including dorsal root ganglion, nodose ganglion and trigeminal ganglion, and in cell processes densely distributed to the superficial layers of the dorsal horn, nucleus of the solitary tract and spinal trigeminal tract. irPNX cell processes were also detected in the skin and myenteric plexus, suggesting a brain-gut and/or brain-skin connection. Pharmacological studies show that PNX-14 injected subcutaneously to the nape of the neck of mice provoked dose-dependent repetitive scratching bouts directed to the back of the neck with the hindpaws. Our result suggests that the peptide PNX-14 and/or PNX-20, may serve as one of the endogenous signal molecules transducing itch sensation. Additionally, results from other laboratories show that exogenous PNX may affect a number of diverse behaviors such as memory formation, depression, reproduction, food-intake and anxiolytic-like behaviors.

Effects of Fe and Co Co-doping on Structural, Magnetic, and Optical Properties of Ti0.9Fe0.1−xCoxO2 Magnetic Semiconductors

A series of six samples with a general formula Ti0.9Fe0.1−xCoxO2 (x = 0.0, 0.02, 0.04, 0.06, 0.08, and 0.1) has been synthesized by solid-state reaction method at annealing temperature of 1150 ∘C for 2 hours. The synthesized samples have been characterized by X-ray diffractometer, Raman spectroscopy, scanning electron microscopy, EDX, vibrating sample magnetometer, and ultraviolet-visible spectroscopy to investigate structural, defective, morphological, elemental, magnetic, and optical properties. Structural analysis revealed dominant structure of rutile with a minor peak of hematite and anatase. An intensity loss and peak broadening of TiO2 (rutile) vibration lines has been observed from Raman analysis. Magnetic characterization showed ferromagnetic behavior at room temperature. Optical characterization revealed blue shift in band gap energy with increasing amount of Co concentration.

Study of Selective Laser Melting of intermetallic TiAl powder using integral analysis

Abstract Selective laser melting (SLM) of intermetallic Ti–48Al–2Cr–2Nb powder is studied using different and complementary methods: (a) experimental parametric analysis (variation of laser power, beam scanning velocity, etc.); (b) metallography including X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM); (c) optical monitoring by infra-red (IR) camera, high speed pyrometer and (d) mathematical modelling. The advantage of the present approach is based on parallel application of diverse methods of analysis using the same SLM set-up and feedstock powder. Also the novelty is related to the preheating of the entire manufacturing module up to 450 °C which is applied before and during the manufacturing of the samples. XRD analysis shows domination of the α2-Ti3Al phase in the initial powder, heat treated powder before SLM and in the developed samples. Some minor peaks of γ-TiAl are identified in SLM parts. EDS analysis confirms the effect of Al evaporation, which intensifies with laser energy input. IR-camera is used for optical monitoring of a single track formation. The geometry of the thermal emission field for different processing parameters is compared with the track geometry. The intensification of hydrodynamic instabilities accompanied by material rejection from the zone of powder consolidation with beam scanning velocity is found. For the first time the evaporation of Al for elevated laser energy input is clearly detected by the IR-camera. Mathematical modelling shows that the same elementary volume of SLM sample can be remelted several times during its fabrication depending on the SLM processing parameters and beam scanning strategy. The maximum values of calculated cooling rates are in the order of 106 °C/s. For the first time the thermo-cycling during SLM parts fabrication is confirmed experimentally by pyrometer measurements.

A set of microsatellite markers to differentiate Plasmodium falciparum progeny of four genetic crosses

BackgroundFour Plasmodium falciparum genetic crosses (HB3×3D7, HB3×Dd2, 7G8×GB4, and 803×GB4) have produced sets of recombinant progeny that are widely used for malaria research, including investigations of anti-malarial drug resistance. It is critical to maintain the progeny free from cross-contamination. Microsatellite polymorphisms can be used to validate parasite identity.ResultsA set of 12 markers was developed that differentiates the parents of the four P. falciparum crosses. This typing set identified distinguishing patterns of inheritance (fingerprints) in segregant collections of 15 progeny clones from HB3×3D7, 32 from HB3×Dd2, 33 from 7G8×GB4, and 81 from 803×GB4. Stronger amplification was observed with shorter relative to longer alleles of individual microsatellites. In experiments with mixed parental DNAs, electropherograms showed that signals of cross-contamination can be missed when minor peaks less than 1/4 or 1/3 the height of the major peak are disregarded by threshold settings commonly used for population studies.ConclusionsMicrosatellite typing is an effective method to check the identity of P. falciparum lines and detect parasite cross-contamination in cultures; however, care must be taken not to ignore minor peaks that can be overlooked. The 12 microsatellite markers presented here provide a rapid and efficient means to distinguish the segregants of laboratory crosses. Fingerprint patterns from these markers are useful to maintain the integrity of diverse parasite lines in and between research laboratories.

The southwestern extension of the Jiao-Liao-Ji belt in the North China Craton: Geochronological and geochemical evidence from the Wuhe Group in the Bengbu area

The Wuhe complex is located at the southeastern margin of the North China Craton. The complex consists of metamorphosed Paleoproterozoic potassic granitoids and supracrustal rocks, of which the latter include the Fengyang and Wuhe groups. Meta-mafic rocks from the lower Wuhe Group have igneous zircon U-Pb ages of 2126 ± 37 Ma with εHf(t) values of −6.22 to +8.38, and xenocrystic zircons of 2.39–2.36 Ga, 2.55–2.54 Ga and 2.77–2.69 Ga. Geochemically, the meta-mafic rocks can be classified into two groups. Group 1 island arc tholeiites display flat to slightly right declined REE patterns and moderately negative Nb, Ta, Zr, and Ti anomalies. Group 2 mature arc calcalkaline basalts display strongly fractionated chondrite-normalized REE patterns and evidently negative Nb, Ta and Ti anomalies. These meta-mafic rocks formed by partial melting of sub-arc depleted mantle wedge which had been modified by slab-derived melts at an active continental margin. Depositional age of the group can be constrained in the period of 2.16–2.10 Ga based on ages of the youngest detrital zircons and latter intrusions. U-Pb ages of detrital zircons yield major age peaks of 2.69 Ga and 2.52 Ga, with minor peaks at 2.88 Ga, 2.78 Ga, 2.35 Ga and 2.17 Ga, most of which are derived from the late Mesoarchean to early Paleoproterozoic granitoids in the Wuhe complex and the Jiaodong Terrane. Metamorphic zircons in the marbles coexisting with garnet amphibolites or granulites occur as either single grains or overgrowth (or recrystallization) rims surrounding magmatic zircon cores and yield ages of 1882 ± 19 Ma to 1844 ± 15 Ma. The comparable ca. 2.1 Ga potassic granites with A-type granite affinity, the ca. 2.1 Ga meta-mafic rocks with arc-like geochemical features, the 2.1–1.9 Ga meta-sedimentary units and the 1.9–1.8 Ga subduction- and collision-related granulite-facies metamorphism suggest that the Wuhe complex and the Jiao-Liao-Ji Belt share the same late Paleoproterozoic tectonic evolution process and the former is the southwestern extension of the latter.