Fungi Associated with the Hemlock Woolly Adelgid, Adelges tsugae, and Assessment of Entomopathogenic Isolates for Management

Fungi associated with the hemlock wooly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), were collected throughout the eastern USA and southern China. Twenty fungal genera were identified, as were 79 entomopathogenic isolates, including: Lecanicillium lecanii (Zimmermann) (Hypocreales: Insertae sedis), Isaria farinosa (Holm: Fries.) (Cordycipitaceae), Beauveria bassiana (Balasamo) (Hyphomycetes), and Fusarium spp (Nectriaceae). The remaining fungal genera associated with insect cadavers were similar for both the USA and China collections, although the abundance of Acremonium (Hypocreaceae) was greater in China. The entomopathogenic isolates were assayed for efficacy against Myzus persicae (Sulzer) (Homoptera: Aphididae) and yielded mortality ranging from 3 to 92%. Ten isolates demonstrating the highest efficacy were further assessed for efficacy against field-collected A. tsugae under laboratory conditions. Overall, two B. bassiana, one L. lecanii, and a strain of Metarhizium anisopliae (Metchnikoff) (Hypocreales: Clavicipitaceae), demonstrated significantly higher efficacy against A. tsugae than the others. Isolates were further evaluated for conidial production, germination rate and colony growth at four temperatures representative of field conditions. All isolates were determined to be mesophiles with optimal temperature between 25–30° C. In general, conidial production increased with temperature, though two I. farinosa produced significantly more conidia at cooler temperatures. When efficacy values were compared with conidial production and temperature tolerances, Agricultural Research Service Collection of Entomopathogenic Fungi (ARSEF) 1080, 5170, and 5798 had characteristics comparable to the industrial B. bassiana strain GHA

Late-onset bloodstream infection and perturbed maturation of the gastrointestinal microbiota in premature infants

Late-onset bloodstream infection (LO-BSI) is a common complication of prematurity, and lack of timely diagnosis and treatment can have life-threatening consequences. We sought to identify clinical characteristics and microbial signatures in the gastrointestinal microbiota preceding diagnosis of LO-BSI in premature infants.Daily faecal samples and clinical data were collected over two years from 369 premature neonates (<32 weeks gestation). We analysed samples from 22 neonates who developed LO-BSI and 44 matched control infants. Next-generation sequencing of 16S rRNA gene regions amplified by PCR from total faecal DNA was used to characterise the microbiota of faecal samples preceding diagnosis from infants with LO-BSI and controls. Culture of selected samples was undertaken, and bacterial isolates identified using MALDI-TOF. Antibiograms from bloodstream and faecal isolates were compared to explore strain similarity.From the week prior to diagnosis, infants with LO-BSI had higher proportions of faecal aerobes/facultative anaerobes compared to controls. Risk factors for LO-BSI were identified by multivariate analysis. Enterobacteriaceal sepsis was associated with antecedent multiple lines, low birth weight and a faecal microbiota with prominent Enterobacteriaceae. Staphylococcal sepsis was associated with Staphylococcus OTU faecal over-abundance, and the number of days prior to diagnosis of mechanical ventilation and of the presence of centrally-placed lines. In 12 cases, the antibiogram of the bloodstream isolate matched that of a component of the faecal microbiota in the sample collected closest to diagnosis.The gastrointestinal tract is an important reservoir for LO-BSI organisms, pathogens translocating across the epithelial barrier. LO-BSI is associated with an aberrant microbiota, with abundant staphylococci and Enterobacteriaceae and a failure to mature towards predominance of obligate anaerobes

Caesarean Section among Referred and Self-Referred Birthing Women: A Cohort Study from a Tertiary Hospital, Northeastern Tanzania.

The inequity in emergency obstetric care access in Tanzania is unsatisfactory. Despite an existing national obstetric referral system, many birthing women bypass referring facilities and go directly to higher-level care centres. We wanted to compare Caesarean section (CS) rates among women formally referred to a tertiary care centre versus self-referred women, and to assess the effect of referral status on adverse outcomes after CS. We used data from 21,011 deliveries, drawn from the birth registry of a tertiary hospital in northeastern Tanzania, during 2000-07. Referral status was categorized as self-referred if the woman had bypassed or not accessed referral, or formally-referred if referred by a health worker. Because CS indications were insufficiently registered, we applied the Ten-Group Classification System to determine the CS rate by obstetric group and referral status. Associations between referral status and adverse outcomes after CS delivery were analysed using multiple regression models. Outcome measures were CS, maternal death, obstetric haemorrhage ≥ 750 mL, postpartum stay > 9 days, neonatal death, Apgar score < 7 at 5 min and neonatal ward transfer. Referral status contributed substantially to the CS rate, which was 55.0% in formally-referred and 26.9% in self-referred birthing women. In both groups, term nulliparous singleton cephalic pregnancies and women with previous scar(s) constituted two thirds of CS deliveries. Low Apgar score (adjusted OR 1.42, 95% CI 1.09-1.86) and neonatal ward transfer (adjusted OR 1.18, 95% CI 1.04-1.35) were significantly associated with formal referral. Early neonatal death rates after CS were 1.6% in babies of formally-referred versus 1.2% in babies of self-referred birthing women, a non-significant difference after adjusting for confounding factors (adjusted OR 1.37, 95% CI 0.87-2.16). Absolute neonatal death rates were > 2% after CS in breech, multiple gestation and preterm deliveries in both referral groups. Women referred for delivery had higher CS rates and poorer neonatal outcomes, suggesting that the formal referral system successfully identifies high-risk birth, although low volume suggests underutilization. High absolute rates of post-CS adverse outcomes among breech, multiple gestation and preterm deliveries suggest the need to target self-referred birthing women for earlier professional intrapartum care

Laboratory Studies of Feeding and Oviposition Preference, Developmental Performance, and Survival of the Predatory Beetle, Sasajiscymnus tsugae on Diets of the Woolly Adelgids, Adelges tsugae and Adelges piceae

The suitability of the balsam woolly adelgid, Adelges piceae Ratzeburg (Hemiptera: Adelgidae) as an alternate mass rearing host for the adelgid predator, Sasajiscymnus tsugae Sasaji and McClure (Coleoptera: Coccinellidae) was studied in the laboratory. This predator is native to Japan and has been introduced to eastern hemlock, Tsuga canadensis (L.) Carrière (Pinales: Pinaceae), forests throughout the eastern United States for biological control of the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), also of Japanese origin. Feeding, oviposition, immature development, and adult long-term survival of S. tsugae were tested in a series of no choice (single-prey) and paired-choice experiments between the primary host prey, A. tsugae, and the alternate host prey, A. piceae. In paired-choice feeding tests, the predator did not discriminate between eggs of the two adelgid species, but in the no choice tests the predator did eat significantly more eggs of A. piceae than those of A. tsugae. S. tsugae accepted both test prey for oviposition and preferred to lay eggs on adelgid infested versus noninfested host plants. Overall oviposition rates were very low (< 1 egg per predator female) in the oviposition preference tests. Predator immature development rates did not differ between the two test prey, but only 60% of S. tsugae survived egg to adult development when fed A. piceae compared to 86% when fed A. tsugae. S. tsugae adult long-term survival was significantly influenced (positively and negatively) by prey type and the availability of a supplemental food source (diluted honey) when offered aestivating A. tsugae sistens nymphs or ovipositing aestivosistens A. piceae adults, but not when offered ovipositing A. tsugae sistens adults. These results suggest that the development of S. tsugae laboratory colonies reared on a diet consisting only of A. piceae may be possible, and that the biological control potential of the predator might be expanded to include management of A. piceae in Christmas tree plantations

Unconventional quantum Hall effect and Berry’s phase 2pi in bilayer graphene.

There are known two distinct types of the integer quantum Hall effect. One is the conventional quantum Hall effect, characteristic of two-dimensional semiconductor systems, and the other is its relativistic counterpart recently observed in graphene, where charge carriers mimic Dirac fermions characterized by Berry’s phase pi, which results in a shifted positions of Hall plateaus. Here we report a third type of the integer quantum Hall effect. Charge carriers in bilayer graphene have a parabolic energy spectrum but are chiral and exhibit Berry’s phase 2pi affecting their quantum dynamics. The Landau quantization of these fermions results in plateaus in Hall conductivity at standard integer positions but the last (zero-level) plateau is missing. The zero-level anomaly is accompanied by metallic conductivity in the limit of low concentrations and high magnetic fields, in stark contrast to the conventional, insulating behavior in this regime. The revealed chiral fermions have no known analogues and present an intriguing case for quantum-mechanical studies

Substrate-induced band gap opening in epitaxial graphene

Graphene has shown great application potentials as the host material for next generation electronic devices. However, despite its intriguing properties, one of the biggest hurdles for graphene to be useful as an electronic material is its lacking of an energy gap in the electronic spectra. This, for example, prevents the use of graphene in making transistors. Although several proposals have been made to open a gap in graphene's electronic spectra, they all require complex engineering of the graphene layer. Here we show that when graphene is epitaxially grown on the SiC substrate, a gap of ~ 0.26 is produced. This gap decreases as the sample thickness increases and eventually approaches zero when the number of layers exceeds four. We propose that the origin of this gap is the breaking of sublattice symmetry owing to the graphene-substrate interaction. We believe our results highlight a promising direction for band gap engineering of graphene.Comment: 10 pages, 4 figures; updated reference

Strain- and Adsorption-Dependent Electronic States and Transport or Localization in Graphene

The chapter generalizes results on influence of uniaxial strain and adsorption on the electron states and charge transport or localization in graphene with different configurations of imperfections (point defects): resonant (neutral) adsorbed atoms either oxygen- or hydrogen-containing molecules or functional groups, vacancies or substitutional atoms, charged impurity atoms or molecules, and distortions. To observe electronic properties of graphene-admolecules system, we applied electron paramagnetic resonance technique in a broad temperature range for graphene oxides as a good basis for understanding the electrotransport properties of other active carbons. Applied technique allowed observation of possible metal-insulator transition and sorption pumping effect as well as discussion of results in relation to the granular metal model. The electronic and transport properties are calculated within the framework of the tight-binding model along with the Kubo-Greenwood quantum-mechanical formalism. Depending on electron density and type of the sites, the conductivity for correlated and ordered adsorbates is found to be enhanced in dozens of times as compared to the cases of their random distribution. In case of the uniaxially strained graphene, the presence of point defects counteracts against or contributes to the band-gap opening according to their configurations. The band-gap behaviour is found to be nonmonotonic with strain in case of a simultaneous action of defect ordering and zigzag deformation. The amount of localized charge carriers (spins) is found to be correlated with the content of adsorbed centres responsible for the formation of potential barriers and, in turn, for the localization effects. Physical and chemical states of graphene edges, especially at a uniaxial strain along one of them, play a crucial role in electrical transport phenomena in graphene-based materials.Comment: 16 pages, 10 figure

Caterpillars and fungal pathogens: two co-occurring parasites of an ant-plant mutualism

In mutualisms, each interacting species obtains resources from its partner that it would obtain less efficiently if alone, and so derives a net fitness benefit. In exchange for shelter (domatia) and food, mutualistic plant-ants protect their host myrmecophytes from herbivores, encroaching vines and fungal pathogens. Although selective filters enable myrmecophytes to host those ant species most favorable to their fitness, some insects can by-pass these filters, exploiting the rewards supplied whilst providing nothing in return. This is the case in French Guiana for Cecropia obtusa (Cecropiaceae) as Pseudocabima guianalis caterpillars (Lepidoptera, Pyralidae) can colonize saplings before the installation of their mutualistic Azteca ants. The caterpillars shelter in the domatia and feed on food bodies (FBs) whose production increases as a result. They delay colonization by ants by weaving a silk shield above the youngest trichilium, where the FBs are produced, blocking access to them. This probable temporal priority effect also allows female moths to lay new eggs on trees that already shelter caterpillars, and so to occupy the niche longer and exploit Cecropia resources before colonization by ants. However, once incipient ant colonies are able to develop, they prevent further colonization by the caterpillars. Although no higher herbivory rates were noted, these caterpillars are ineffective in protecting their host trees from a pathogenic fungus, Fusarium moniliforme (Deuteromycetes), that develops on the trichilium in the absence of mutualistic ants. Therefore, the Cecropia treelets can be parasitized by two often overlooked species: the caterpillars that shelter in the domatia and feed on FBs, delaying colonization by mutualistic ants, and the fungal pathogen that develops on old trichilia. The cost of greater FB production plus the presence of the pathogenic fungus likely affect tree growth

Defensive responses by a social caterpillar are tailored to different predators and change with larval instar and group size

Gregariousness in animals is widely accepted as a behavioral adaptation for protection from predation. However, predation risk and the effectiveness of a prey’s defense can be a function of several other factors, including predator species and prey size or age. The objective of this study was to determine if the gregarious habit of Malacosoma disstria caterpillars is advantageous against invertebrate natural enemies, and whether it is through dilution or cooperative defenses. We also examined the effects of larval growth and group size on the rate and success of attacks. Caterpillars of M. disstria responded with predator-specific behaviors, which led to increased survival. Evasive behaviors were used against stinkbugs, while thrashing by fourth instar caterpillars and holding on to the silk mat by second instar caterpillars was most efficient against spider attacks. Collective head flicking and biting by groups of both second and fourth instar caterpillars were observed when attacked by parasitoids. Increased larval size decreased the average number of attacks by spiders but increased the number of attacks by both stinkbugs and parasitoids. However, increased body size decreased the success rate of attacks by all three natural enemies and increased handling time for both predators. Larger group sizes did not influence the number of attacks from predators but increased the number of attacks and the number of successful attacks from parasitoids. In all cases, individual risk was lower in larger groups. Caterpillars showed collective defenses against parasitoids but not against the walking predators. These results show that caterpillars use different tactics against different natural enemies. Overall, these tactics are both more diverse and more effective in fourth instar than in second instar caterpillars, confirming that growth reduces predation risk. We also show that grouping benefits caterpillars through dilution of risk, and, in the case of parasitoids, through group defenses. The decreased tendency to aggregate in the last larval instar may therefore be linked to decreasing predation risk

UK adults' implicit and explicit attitudes towards obesity: a cross-sectional study.

Background: Anti-fat attitudes may lead to stigmatisation of and lowered self-esteem in obese people. Examining anti-fat attitudes is warranted given that there is an association with anti-fat behaviours. Previous studies, mainly outside the UK, have demonstrated that anti-fat attitudes are increasing over time. Methods: The study was cross-sectional with a sample of 2380 participants (74.2 % female; aged 18–65 years). In an online survey participants reported demographic characteristics and completed a range of implicit and explicit measures of obesity related attitudes. Results: Perceptions of obesity were more negative than reported in previously. Main effects indicated more negative perceptions in males, younger respondents and more frequent exercisers. Attitudes about obesity differed in relation to weight category, and in general were more positive in obese than non-obese respondents. Conclusions: This is the first study to demonstrate anti-fat attitudes across different sections of the UK population. As such, this study provides the first indication of the prevalence of anti-fat attitudes in UK adults. Interventions to modify these attitudes could target specific groups of individuals with more negative perceptions as identified here. Future work would be useful that increases understanding of both implicit and explicit attitudes towards obesity