Average Susceptibility Research Articles

Household susceptibility to hydrological change in the Lower Mekong Basin

The hydrological conditions of the Lower Mekong Basin support a multitude of ecosystem services. Processes that influence water flow in the Mekong River will thus have implications for the tens of millions of people whose livelihoods depend on these services. This study presents an assessment of livelihood susceptibility to hydrological change in the Lower Mekong Basin. Using an index‐based approach, susceptibility scores were calculated for 2,703 households. Using those scores, we compared average household susceptibility across the basin, among countries and among eco‐zones. Due to their greater livelihood dependency on water‐related activities, mean household susceptibility was higher in Vietnam than in Cambodia, Laos, or Thailand. Households in Northern Laos also had high susceptibility, which was attributed to their low adaptive capacity. The findings suggest that policies aimed at reducing vulnerability to hydrological change in the Lower Mekong Basin should account for geographic context. Further, they highlight how policies may be able to strategically target the most susceptible households, but that poorly designed policies have the potential to exacerbate vulnerability. In the face of high uncertainty surrounding hydrological change in the Lower Mekong Basin, our assessment of susceptibility should help inform precautionary water management policies and provide baseline information needed for more comprehensive vulnerability assessments.

Coseismic landslide susceptibility assessment using geographic information system

Indonesia is one of the most earthquake prone countries in the world. More than 14,000 earthquakes of magnitude greater than 5 occurred in Indonesia between 1897 and 2009. Earthquakes are a major cause of slope instability eventually triggering coseismic landslides, which cost 1.5 million US$/ year in Java: one of the most densely islands in Indonesia. This paper aims to assess coseismic landslide susceptibility using Geographic Information System (GIS) on the western flank of Baturagung Escarpment, 8 km southeast of the Yogyakarta City, a data sparse area. Therefore, we have used a probabilistic seismic hazard analysis to calculate the peak ground accelerations, while the coseismic landslide susceptibility analysis was done by the scoring method in the GIS adopted from Mora and Vahrson model (Costa Rica), which is well adopted for data sparse areas. The west flank of Baturagung Escarpment is dominated by moderate level of coseismic landslide with an average Coseismic Landslide Susceptibility Level (CLSL) of 33–162. The upper slope of Baturagung Escarpment, which consists of Semilir Formation has the CLSL of 163–512, corresponding to medium level CLSL (Mora and Vahrson model). The low level CLSL is mainly located on the foot slopes of Baturagung Escarpment, while the alluvial and colluvial plains located along the Opak River have very low CLSL (0–6). Based on the mapped landslide occurrence, the landslides tend to occur in the zone of moderate CLSL and they are distributed along the border between moderate and low coseismic landslide zone, meaning that the change on local condition could be playing an important role in triggering coseismic landslide.

Fidelity of the diagonal ensemble signals the many-body localization transition.

In this work, we use exact matrix diagonalization to explore the many-body localization (MBL) transition in a random-field Heisenberg chain. We demonstrate that the fidelity and fidelity susceptibility can be utilized to characterize the interaction-driven many-body localization transition in this closed spin system which is in agreement with previous analytical and numerical results [S. Garnerone, N. T. Jacobson, S. Haas, and P. Zanardi, Phys. Rev. Lett. 102, 057205 (2009)PRLTAO0031-900710.1103/PhysRevLett.102.057205; P.Zanardi and N. Paunkovic, Phys.Rev. E 74, 031123 (2006)PLEEE81539-375510.1103/PhysRevE.74.031123]. In particular, instead of ground-state fidelity, we test the fidelity between two diagonal ensembles related by a small parameter perturbation δh, it is special that here the parameter perturbation δh_{i} for each site are random variables like h_{i}. It shows that fidelity of the diagonal ensemble develop a pronounced drop at the transition. We utilize fidelity to estimate the critical disorder strength h_{c} for different system size, we get h_{c}∈ [2.5,3.9] and get a power-law decay with an exponent of roughly -1.49(2) for system size N, and can extrapolate h_{c}^{inf} of the infinite system is about 2.07 which all agree with a recent work by Huse and Pal, in which the MBL transition in the same model was predicted to be hc [2,4]. We also estimate the scaling of maximum of averaged fidelity susceptibility as a function of system size N, it shows a power law increase with an exponent of about 5.05(1).

Effects of shock pressure and temperature on titanomagnetite from ICDP cores and target rocks of the El’gygytgyn impact structure, Russia

The aim of this study was to investigate the effect of meteorite impacts on magnetic properties including magnetic susceptibility and the Verwey transition of Ti-poor titanomagnetite of volcanic rocks from the 3.6 Ma old El’gygytgyn impact structure located in the Okhotsk-Chukotka volcanic belt in north-eastern Russia. The target rocks consist mainly of rhyolite with some andesites, and is a rare example of impact structures within volcanic target rocks on Earth. 27 samples from outside the crater, the crater rim and from the depth interval 316 to 517 m below lake bottom (mblb) of the El’gygytgyn ICDP drilling were studied. A significant decrease of the average specific magnetic susceptibility by around 90% was observed between felsic volcanic rocks from the surface (18.1 × 10-6 m3/kg) and the drill cores from near the crater central uplift (1.9 × 10-6 m3/kg). Ferrimagnetic Fe-Ti oxide assemblages (Verwey transition temperature, TV: -161 to -150°C, Curie temperature, TC: 451 to 581°C), occurring in all studied samples, differ significantly. At the surface titanomaghemite is ubiquitously associated with titanomagnetite. The drill cores lack titanomaghemite, but either show a transformation into titanomagnetite and ilmenite or a strong fragmentation associated with a second TV between -172 and -188°C. Reversible curves of temperature dependence of magnetic susceptibility in the suevite indicate high depositional temperatures of at least 500°C. In the polymict and monomict impact breccia mechanical deformation of titanomagnetite and temperatures of at least 200-350°C related to the shock are suggested from temperature dependent magnetic susceptibility cycling. Lowtemperature oxidation along strongly brecciated grain surfaces in titanomagnetite is suggested to cause the lower TV and we suggest that this phenomenon is related to postimpact hydrothermal activity. The strong magnetic susceptibility decrease at El’gygytgyn is mainly influenced by shock, and post-impact hydrothermalism causes a significant additional depletion. These observations explain why magnetic lows are a ubiquitous phenomenon over impact structures.

Five-Year Antimicrobial Susceptibility Trends Among Bacterial Isolates from a Tertiary Health-Care Facility in Kigali, Rwanda.

Antimicrobial resistance (AMR) is a global public health threat. There is limited information from Rwanda on AMR trends. This longitudinal study aimed to describe temporal trends of antibiotic susceptibility among common bacteria. We collated the antimicrobial susceptibility results of bacteria cultured from clinical specimens collected from inpatients and outpatients and submitted to the microbiology laboratory at King Faisal Hospital, Kigali, Rwanda, from January 1, 2009, to December 31, 2013. Differences in antimicrobial susceptibility between the first and fifth year of the study for each bacterial species was assessed using χ2 test. Of 5,296 isolates collected, 46.7% were Escherichia coli, 18.4% were Klebsiella spp., 5.9% were Acinetobacter spp., 7.1% were Pseudomonas spp., 11.7% were Staphylococcus aureus, and 10.3% were Enterococcus spp. Colistin and imipenem had greatest activity against gram-negative bacteria. Acinetobacter spp. showed the greatest resistance profile to antimicrobials tested, relative to other gram-negative bacteria. Vancomycin retained excellent activity against S. aureus and Enterococcus species (average susceptibility was 100% and 99.4%, respectively). Trend analysis determined that resistance to imipenem increased significantly among Klebsiella, E. coli, Pseudomonas, and Acinetobacter isolates; there was also rising resistance to colistin among E. coli and Pseudomonas species. Only E. coli demonstrated increased resistance to gentamicin. For gram-positive pathogens, vancomycin susceptibility increased over time for Enterococcus species, but was unchanged for S. aureus Our data suggest that resistance to imipenem and colistin are rising among gram-negative bacteria in Rwanda. Proper infection control practices and antimicrobial stewardship will be important to address this emerging threat.

Potential of quantitative susceptibility mapping for detection of prostatic calcifications.

To evaluate whether quantitative susceptibility (QSM) may be used as an alternative to computed tomography (CT) to detect calcification in prostate cancer patients. Susceptibility map calculation was performed using 3D gradient echo magnetic resonance imaging (MRI) data from 26 patients measured at 3T who previously received a planning CT of the prostate. Phase images were unwrapped using Laplacian-based phase unwrapping, the background field was removed with the V-SHARP method, and susceptibility maps were calculated with the iLSQR method. Two blinded readers were asked to identify peri- and intraprostatic calcifications. Average mean and minimum susceptibility values (referenced to iliopsoas muscle) of calcifications were -0.249 ± 0.179 ppm and -0.551 ± 0.323 ppm, and average mean and maximum intensities in CT images were 319 ± 164 HU and 679 ± 392 HU. Twenty-one and 17 out of 22 prostatic calcifications were identified using susceptibility maps and magnitude images, respectively, as well as more than half of periprostatic phleboliths depicted by CT. Calcifications in the prostate and its periphery were quantitatively differentiable from noncalcified prostate tissue in CT (mean values for calcifications / for noncalcified tissue: 71 to 649 / -1 to 83 HU) and in QSM (mean values for calcifications / for noncalcified tissue: -0.641 to 0.063 / -0.046 to 0.181 ppm). Moreover, there was a significant correlation between susceptibility values and CT image intensities for calcifications (P < 0.004). Prostatic calcifications could be well identified with QSM. Susceptibility maps can be easily obtained from clinical prostate MR protocols that include a 3D gradient echo sequence, rendering it a promising technique for detection and quantification of intraprostatic calcifications. 1 J. Magn. Reson. Imaging 2017;45:889-898.

CHARACTERISTICS ASSOCIATED WITH RISK OF EXTINCTION IN BRAZILIAN ATLANTIC FOREST MAMMALS

CHARACTERISTICS ASSOCIATED WITH RISK OF EXTINCTION IN BRAZILIAN ATLANTIC FOREST MAMMALS The susceptibility of a species to extinction can be related to three groups of characteristics, namely, distribution (endemism and restricted distribution), biology (body size, trophic guild, reproduction) and human impacts (hunting). A survey of these characteristics was made in terrestrial mammals of the Brazilian Atlantic Forest to determine their distribution in individual species of each order, and estimate which orders have higher expected average proportion of species susceptible to extinction. These estimates were compared with official threatened species lists. Principal components analysis (PCA) was used to find which characteristics best define the proportional susceptibility to extinction in each order. Spearman´s correlation was used to determine if global, national, and state evaluation scales affected the relationship between the expected average susceptibility and the listed threatened species for each characteristic. Lastly, linear regression was used to test the dependence of the number of threatened species to the total number of species with each characteristic of susceptibility. PCA grouped species with larger body size, wider distribution, and more hunting in a given order and grouped smaller body size, narrower distribution and less hunting on the same axis. The second component grouped the orders most affected by characteristics which increased susceptibility to extinction and the orders least affected. There was a significant positive correlation (p

Anthropogenic particle dispersions in topsoils of the Middle Nile Delta: a preliminary study on the contamination around industrial and commercial areas in Egypt

Increased industrialization has adversely affected various components of the environment including soil, which is the ultimate site of settling and accumulation of fly ash. Fine respirable size particles in the atmosphere are detrimental to human health and their ultimate accumulation in the soil leads to soil pollution. In this study, these particles were identified, quantified and subjected to intensive analysis by SEM/EDX. Accordingly, the physical and chemical characteristics, the origin and the pathway of such particulates are documented for the Middle Nile Delta using the magnetic susceptibility as proxy for the industrial emissions. The average bulk density of magnetic spherules varies between 4.4 ± 0.7, 4.8 ± 0.9 and 5.4 ± 0.6 g/cm3 for the >125, 63–125 and 36–63 μm fractions, respectively, and consists predominantly of iron oxides with variable amounts of Ti, Si, Mn, Mg, Al, Ca, Cr and Cu. Their attached grains and adhesive materials are commonly composed of various contents of Si, Al, Fe, Ca, P, Zn, Ba and S depending on their origin. The results indicated that most surface soil samples are enhanced magnetically than the natural local background magnetic signal due to atmospherically deposited urban dust. The industrial sites are characterized by highest average magnetic susceptibility value (47 × 10−5 m3g−1) combined with highest concentration of magnetic spherules (66 sph.g−1). Moreover, the residential area surrounding industrial zones—particularly those located in the windblown (SE) direction—is seriously affected by industrial dust. This study provides a database to evolve strategies for remedial measures to minimize environmental degradation.

Materials with low DC magnetic susceptibility for sensitive magnetic measurements

Materials with very low DC magnetic susceptibility have many scientific applications. To our knowledge however, relatively little research has been conducted with the goal to produce a totally nonmagnetic material. This phrase in our case means after spatially averaging over macroscopic volumes, it possesses an average zero DC magnetic susceptibility. We report measurements of the DC magnetic susceptibility of three different types of nonmagnetic materials at room temperature: (I) solutions of paramagnetic salts and diamagnetic liquids, (II) liquid gallium–indium alloys and (III) pressed powder mixtures of tungsten and bismuth. The lowest measured magnetic susceptibility among these candidate materials is in the order of 10−9 cgs volume susceptibility units, about two orders of magnitude smaller than distilled water. In all cases, the measured concentration dependence of the magnetic susceptibility is consistent with that expected for the weighted sum of the susceptibilities of the separate components within experimental error. These results verify the well-known Wiedemann additivity law for the magnetic susceptibility of inert mixtures of materials and thereby realize the ability to produce materials with small but tunable magnetic susceptibility. For our particular scientific application, we are also looking for materials with the largest possible number of neutrons and protons per unit volume. The gallium–indium alloys fabricated and measured in this work possess to our knowledge the smallest ratio of volume magnetic susceptibility to nucleon number density per unit volume for a room temperature liquid, and the tungsten-bismuth pressed powder mixtures possess to our knowledge the smallest ratio of volume magnetic susceptibility to nucleon number density per unit volume for a room temperature solid. This ratio is a figure of merit for a certain class of precision experiments that search for possible exotic spin-dependent forces of Nature.

You can run, you can hide: The epidemiology and statistical mechanics of zombies.

We use a popular fictional disease, zombies, in order to introduce techniques used in modern epidemiology modeling, and ideas and techniques used in the numerical study of critical phenomena. We consider variants of zombie models, from fully connected continuous time dynamics to a full scale exact stochastic dynamic simulation of a zombie outbreak on the continental United States. Along the way, we offer a closed form analytical expression for the fully connected differential equation, and demonstrate that the single person per site two dimensional square lattice version of zombies lies in the percolation universality class. We end with a quantitative study of the full scale US outbreak, including the average susceptibility of different geographical regions.

A record of Pleistocene diatom preservation from the Amundsen Sea, West Antarctica with possible implications on silica leakage

article i nfo Accumulation of fossil diatoms in marine sediments is variably affected by the production and dissolution of diatom frustules across space and time. No quantitative proxy exists for estimating the amount of silica lost to dissolution in Southern Ocean sediment cores. To address this gap, cultured valves of Fragilariopsis kerguelensis, the dominant planktonic diatom in the Pleistocene to recent Southern Ocean, were dissolved progressively under controlled laboratory conditions. Expansion, and eventual conjoining, of the areolae of F. kerguelensis advances through several phases, which are presented herein as a measure of diatom dissolution. In order to evaluate the validity of laboratory methods, this proxy is applied to sediments from piston core PS58/254 from the Amundsen Sea. Dissolution-induced degradation morphologies from laboratory experiments are seen to be identical to those preserved naturally in sediments, thus suggesting the laboratory conditions accurately reflect the natural process of dissolution. These resultsrepresentthe firstapplication of afullyquantitativeproxyfordiatomdissolution toSouthernOcean sediments, revealing that meaningful paleoceanographic data can be generated via taphonomic analysis of diatom valves. Intensity of diatom dissolution in core PS58/254 does not correspond to the relative abundance of any diatom species, clay mineralogy, or linear sedimentation rates. However, a correlation does exist between glacial cyclicity and diatom dissolution, indicating that variation in average wall thickness and susceptibility to dissolution reflects primary conditions during formation of the silica wall, transit through the water column, and eventual deposition. Higher overall silica dissolution is observed during each glacial period and enhanced silica preservation during interglacials. This result is consistent with the predictions of the silicic acid leakage hypothesis (SALH), whereby reduced rates of Si usage in the Southern Ocean lead to shifts in marine primary productivity in the tropics from coccolithophoriddominance duringinterglacialstodiatomdominanceduringglacials.Thiswouldfuela decrease in atmospheric pCO2duringglacials. Silica acidleakage isdrivenbya decreaseinthe Si:Nratioofdiatoms,caused by increased iron input to glacial-aged Southern Ocean waters. This resulted in more lightly silicified diatom valves in the Southern Ocean, which dissolved more quickly in the upper water column, thereby maintaining the high silica content of glacial-aged SO waters, and allowing for export of Si to upwelling zones in the lower latitudes.

Charakterystyka genotypów pszenicy ozimej o zróżnicowanym stopniu odporności na Fusarium (Fusarium ssp.) pod kątem odporności na mączniaka prawdziwego (Blumeria graminis)

The field experiment was carried out in 2010–2012 at the Experimental Station of the Department of Genetics and Plant Breeding, Poznan University of Life Sciences. The study was designed to evaluate the degree of infection by powdery mildew (Blumeria graminis) on 25 winter wheat genotypes characterized by high and varied resistance to Fusarium. On average, the lowest infection by powdery mildew, amounting to 4 degrees in a 9-degree scale was observed on the two registered Polish varieties (Ostroga and Natula), 4 genotypes from Austria, 2 from Hungary and one from Sweden, while the highest infection in the case of two Polish varieties – Muszelka and Sukces. Low FHB (Fusarium head blight) index was characterized by certain genotypes considered as resistant and three Polish varieties: Fregata, Sukces and Ostroga. Wheat genotypes poorly infected by Fusarium with the average or low susceptibility to powdery mildew were: Ertus, Fregata, 20816, Poros, Ostroga and Kubanskaya 122.

Nitrate-processing and characterization of a cobalt-doped barium tin oxide perovskite: Magnetic, transport and photoelectrochemical properties

The perovskite BaSn0.95Co0.05O3−δ, prepared by nitrate route, crystallizes in a cubic symmetry with a slight isotropic contraction of the host lattice. The oxygen crystal field splits the Co3+: 3d orbital by a value of 2.02eV with a low spin configuration of Co3+ (t2g6eg0). The average magnetic susceptibility (~2×10−5emucgsmol−1) is temperature independent, in conformity with itinerant electrons behavior. The sample is nominally non-stochiometric and the conductivity follows a thermally activated hopping of lattice polaron with an activation energy of 19meV. The thermal variation of the thermo-power suggests a finite density of states at the Fermi level. The zero temperature conductivity is finite and the charge carriers in localized states are thermally excited into extended states above the mobility edge. A variable range hopping is predicted at low temperature from the non-linearity of ln(σ) versus T−1 plot while the hump observed near 25K is ascribed to the phonon drag. The photo-electrochemical characterization in KOH medium indicates p type behavior with a flat band of −0.21VSCE and a donor density of 6.95×1020cm−3. The electrochemical impedance spectroscopy is undertaken and the response is modeled by an equivalent circuit with the predominance of the bulk contribution. The depressed semicircle is attributed to the faradic charge transfer with a constant phase element (CPE) while the straight line at low frequencies is due to the Warburg diffusion.

On the definition and utilization of heritable variation among hosts in reproduction ratio R0 for infectious diseases.

Infectious diseases have a major role in evolution by natural selection and pose a worldwide concern in livestock. Understanding quantitative genetics of infectious diseases, therefore, is essential both for understanding the consequences of natural selection and for designing artificial selection schemes in agriculture. The basic reproduction ratio, R0, is the key parameter determining risk and severity of infectious diseases. Genetic improvement for control of infectious diseases in host populations should therefore aim at reducing R0. This requires definitions of breeding value and heritable variation for R0, and understanding of mechanisms determining response to selection. This is challenging, as R0 is an emergent trait arising from interactions among individuals in the population. Here we show how to define breeding value and heritable variation for R0 for genetically heterogeneous host populations. Furthermore, we identify mechanisms determining utilization of heritable variation for R0. Using indirect genetic effects, next-generation matrices and a SIR (Susceptible, Infected and Recovered) model, we show that an individual's breeding value for R0 is a function of its own allele frequencies for susceptibility and infectivity and of population average susceptibility and infectivity. When interacting individuals are unrelated, selection for individual disease status captures heritable variation in susceptibility only, yielding limited response in R0. With related individuals, however, there is a secondary selection process, which also captures heritable variation in infectivity and additional variation in susceptibility, yielding substantially greater response. This shows that genetic variation in susceptibility represents an indirect genetic effect. As a consequence, response in R0 increased substantially when interacting individuals were genetically related.

Magnetic mineralogy of pyroxenite xenoliths from Hannuoba basalts, northern North China Craton: Implications for magnetism in the continental lower crust

Studies of the petrology, mineral chemistry, and rock magnetic properties of nine pyroxenite xenoliths from Hannuoba basalts, northern North China Craton, have been made to determine the magnetization signature of the continental lower crust. These pyroxenites are weakly magnetic with low average susceptibility (χ) and saturation isothermal remanent magnetization (Mrs) of 39.59 × 10−8 m3 kg−1 and 12.05 × 10−3 Am2 kg−1, respectively. The magnetic minerals are mainly magnetite, pyrrhotite, and Fe-rich spinel, which significantly contribute to χ and natural remanent magnetization. Magnetite occurs as interstitial microcrystals together with zeolite aggregates, indicating a secondary origin in a supergene environment. In contrast, pyrrhotite and Fe-rich spinel were formed prior to the xenoliths' ascent to the surface, as evidenced by their dominant occurrence as tiny inclusions and thin exsolution lamellae in pyroxene. The Fe-rich spinel has ~ 50% mole fraction of Fe3O4 and corresponds to the strongest magnetization, and its coexistence with Mg-rich spinel implies a reheating event due to the underplating of basaltic magma. Besides, armalcolite and ilmenite were found in the reaction rims between xenoliths and the basalt, but they contribute little to the whole rock magnetization. However, these pyroxenite xenoliths would be nonmagnetic at in situ depths, as well as peridotite and mafic granulite xenoliths derived from the crust-mantle transition zone (~ 32–42 km). Therefore, we suggest the limiting depth of magnetization at the boundary between weakly magnetic deep-seated (lower crust and upper mantle) xenoliths and strongly magnetic Archean granulite facies rocks (~ 32 km) in Hannuoba, northern North China Craton.

Magnetic properties of two soil profiles from Yan’an, Shaanxi Province and their implications for paleorainfall reconstruction

The physical and chemical properties of soils are closely controlled by the climate factors and thus are significant for paleoclimate reconstruction. In this study, two adjacent soil profiles (LP and LPM) with different slopes from Yan’an, Shaanxi Province, were investigated using magnetic methods to determine the impact of topography on magnetic properties of soil. Our results show that although LP and LPM have similar magnetic minerals and grain size distribution, both the average and maximum magnetic susceptibility (χ) of LP are almost doubled compared to those of LPM. In addition, the ratios of susceptibility enhancement to the background (E χ ) for LP and LPM are 2.27 and 2.04, respectively; the ratios of saturation isothermal remnant magnetization (SIRM) enhancement (E SIRM) for these two profiles are 1.80 and 1.86, respectively. The slopes of the linear regression trends between frequency-dependent susceptibility (χ FD) and “hard” isothermal remnant magnetization (HIRM) (χ FD/HIRM), Anhysteretic remnant magnetization (ARM) and HIRM (ARM/HIRM), are almost free from the effect of parent material. χ FD/HIRMs for LP and LPM are 28.7×10−5 and 28.9×10−5 A m−1, respectively; ARM/HIRMs are 0.35 and 0.33 for LP and LPM, respectively. These results demonstrate that parameters, χ FD/HIRM, ARM/HIRM, E χ and E SIRM, are affected less by parent material and topography, which are better than the χ for bulk samples to indicate the paleoclimatic conditions (e.g., the paleorainfall) in a large-scale region.

A Multicenter Study of Beta-Lactamase Resistant Escherichia coli and Klebsiella pneumoniae Reveals High Level Chromosome Mediated Extended Spectrum β Lactamase Resistance in Ogun State, Nigeria.

As a result of the ever increasing problem of multiresistant bacteria, we instituted a surveillance program with the aim of identifying the basic molecular properties of ESBL in our environment. About 197 isolates of Escherichia coli and Klebsiella pneumoniae were selected and tested for ESBL production and antimicrobial susceptibility. Plasmid profiles were determined and curing ability was tested. ESBL prevalence was 26.4% for all isolates tested, with E. coli having a greater proportion. There was absolute resistance to ampicilin, tetracycline, and co-trimaxole among tested isolates. There was above average susceptibility to the 2nd and 3rd generation cephalosporins. Plasmid profiles of tested isolates ranged from 9 kbp to 26 kbp with average of 14.99 ± 2.3 kbp for E. coli and 20.98 ± 1.8 kbp K. pneumoniae, 9.6% of ESBL positive E. coli plasmids were cured, while 3.9% of K. pneumoniae plasmids were cured after treatment. The present study shows an upsurge in ESBL acquisition by gram negative bacteria and evidence of cocirculation of varying subtypes of ESBL with both plasmid transmissible and chromosome encoded subtypes. This calls for universal surveillance and more effort towards molecular epidemiology of this public health treatment.

Genetic variation in Eucalyptus camaldulensis and E. tereticornis for early growth and susceptibility to the gall wasp Leptocybe invasa in China

The gall wasp Leptocybe invasa is a major insect pest on plantation Eucalyptus in many countries. Since appearing in China in 2007 it has had major impacts on commercial plantations—some commonly planted Eucalyptus varieties have proven particularly susceptible, including hybrids involving Eucalyptus camaldulensis and E. tereticornis parent species. Intra-specific variation within each species for L. invasa susceptibility was examined in two seed source and family trials in southwest of Guangdong. The E. camaldulensis trial included 101 seedlots representing five natural stand and six seed orchard sources which also represented three sub-specific taxa. The E. tereticornis trial included 143 seedlots representing 11 natural stand and four seed orchard sources, including breeding seed orchards in China. Both trials were assessed for susceptibility to L. invasa along with height at age 9 months. Sub-specific taxa within E. camaldulensis differed significantly (P < 0.01) in L. invasa susceptibility but not height or survival; subsp. acuta had the lowest average susceptibility and subsp. simulata and obtusa were of intermediate susceptibility whilst material of uncertain sub-specific taxa from India had the highest average susceptibility. In E. tereticornis regions of origin and seed sources within regions differed significantly (P < 0.01) for both L. invasa susceptibility and height; the region China (all somewhat improved sources) had both the best average height growth and lowest susceptibility whilst the region Australia (all natural stand sources) proved inferior to China for both average susceptibility and height. A strong significant correlation was found between seed source average L. invasa susceptibility and annual rainfall at seed source geographic origin in E. tereticornis (r = −0.873; P < 0.01), implying that seedlots from higher rainfall environments are markedly less susceptible to L. invasa. The equivalent parameter in E. camaldulensis was also strong (r = −0.730) though not significant, perhaps due to having only five data points available. Differences between families within seed sources for both L. invasa susceptibility and height growth were also highly significant (P < 0.01) with the former trait proving moderately to strongly heritable (h i 2 = 0.54 ± 0.40 in E. camaldulensis; 0.52 ± 0.50 in E. tereticornis). Height had low to moderate heritability in both species (h i 2 = 0.11 ± 0.15 and 0.26 ± 0.08 respectively). Tree height and L. invasa susceptibility showed a moderate negative (favourable) genetic correlation in E. camaldulensis (−0.33 ± 0.64) and a moderate to strong negative (favourable) genetic correlation in E. tereticornis (−0.47 ± 0.31). Corresponding phenotypic correlations, though significant, were somewhat weaker (−0.16 and −0.29 respectively), indicating a trend for taller trees to have lower levels of L. invasa susceptibility.

Monitoring Insecticide Resistance in Biotype B ofBemisia tabaci(Hemiptera: Aleyrodidae) in Florida

Biotype B of the sweetpotato whitefly (SPWF), Bemisia tabaci (Gennadius) (also known as the silverleaf whitefly, B. argentifolii Bellows & Perring), is the key pest of tomatoes in south Florida, primarily as a vector of the begomovirus Tomato yellow leaf curl virus (TYLCV). Insecticides are most often used to manage the SPWF and TYLCV. A resistance monitoring program that was initiated in Florida in 2000 was continued from 2008 to 2010 and included 4 neonicotinoid insecticides (imidacloprid, thiamethoxam, dinotefuran, and acetamiprid), the insect growth regulator buprofezin, the pyrethroid bifenthrin, and the organochlorine endosulfan. Ten field populations in 2008 and 9 each in 2009 and 2010 were established with nymphal infested foliage and were tested for susceptibility using a systemic uptake, cut-leaf petiole bioassay with adults for the neonicotinoids; a leaf-dip bioassay with 2nd instars for buprofezin; and a vial bioassay with adults for bifenthrin and endosulfan. Each field population was exposed to the LC50 and LC95 of a known susceptible laboratory colony for each respective insecticide and mortality was compared with that at the same doses predicted from probit analyses of field populations tested in 2007. T-tests were used to determine the significance of differences between the mean mortality at the LC values of each field collected colony compared to the respective LC values of the laboratory susceptible strain. T-tests were also used to determine the significance of differences between the mean of the predicted mortality at the LC values of field collected populations in 2007 and the means of the LC values of field collected populations in 2008–2010 for each insecticide. Results indicated that, based on mortality averaged over all populations evaluated, all of the neonicotinoids indicated decreases in average susceptibility in 2008 and 2009 compared with the 2007 values, although the differences were less for dinotefuran and acetamiprid. The lowest average of mortality at both the LC50 and LC95 in 2008 and 2009 occurred for imidacloprid and thiamethoxam. These neonicotinoids had been in use longer than either of the other two. Mortality values for bifenthrin suggested an overall increase in field susceptibility in 2008 and 2009 while values for endosulfan suggested no change. There were no data predicted for buprofezin in 2007, but the 2008 average mortalities at the LC50 and LC95 were 0.438 and 0.802, respectively, indicating that field susceptibility was at an acceptable level. In 2010 the average susceptibility to the neonicotinoids appeared to have increased compared with previous years; however, the field populations tended to be evaluated after they had been reared in the laboratory without exposure to insecticides for more generations than in previous years. Despite this, average susceptibility to endosulfan appeared to decrease. The results showed the utility of using predicted LC50 and LC95 values, over the use of full dose range, for monitoring changes in susceptibility in field populations thru time. The data presented here provide important information aid to growers and producers in making decisions on insecticide usage.

Orientational Distribution of Cellulose Nanocrystals in a Cellulose Whisker As Studied by Diamagnetic Anisotropy

The orientational distribution of cellulose nanocrystals (CNCs) in a cellulose whisker (CW) was investigated by means of the X-ray diffraction of magnetically oriented samples of CWs. A cellulose sample (Whatman CF11) was hydrolyzed and fractionated to prepare three different CW samples with a size ranging from ca. 10 to 100 μm. Each of the fractions that were suspended in a liquid matrix was aligned under a static or a rotating magnetic field, and the matrix was solidified to prepare magnetically oriented microcrystal arrays (MOMAs). Then, the MOMAs were investigated by X-ray diffraction measurements. By analysis of the diffraction patterns, it is concluded that the c-axes of the CNCs are uniaxially distributed within a CW and that the orientational order increases with decreasing CW size. The average anisotropic magnetic susceptibility ⟨χa⟩ of the CWs was expressed in terms of their size and of the X-ray azimuthal half width. Using these expressions, a correlation length for the orientation of CNCs in a CW was determined. The proposed method enables one to investigate the orientational order in a macrofiber at arbitrary scales by magnetically aligning the small fragments segmented from the macrofiber.