Parasitoids with potential for the control of Hypsipyla grandella in Latin America

Hypsipyla grandella (Zeller) is the most important insect pest of the Meliaceae in the Neotropics. This paper reviews the information on H. grandella parasitoids in Latin America and the Caribbean. Preliminary data on the parasitoid complex in Turrialba, Costa Rica, are presented, where apparent parasitisation of H. grandella during 1995–1996 reached 36%. The lowest level of parasitisation occurred during the dry season. The parasitoid Apanteles sp. (= Hypomicrogaster hypsipylae de Santis?) (Hymenoptera: Braconidae) was the most abundant larval parasitoid with a mean of 22 parasitoids per parasitised larva and a sex ratio of 3:1 females to males. Brachymeria conica Ashmead (Hymenoptera: Chalcididae) was found parasitising pupae, but at low frequency

The presence of ultrasonic harmonics in the calls of the rifleman (Acanthisitta chloris)

Ultrasonic vocalisations (frequencies > 20 kHz) have been extensively studied in the context of echolocation by bats and other mammals (Sales & Pye 1974; Wilson & Hare 2004). Ultrasonic calls have also been recorded from birds, including the blue-throated hummingbird ( Lampornis clemenciae ) (Pytte et al. 2004), where it was first thought that individuals made use of high pitch calls to avoid masking by background noise in a visually obscured environment. Similarly, city-dwelling great tits ( Parus major ) use song with a higher minimum frequency (although not ultrasonic) compared to woodland birds to communicate with conspecifics to avoid the predominantly low-frequency background noise in the city (Slabbekorn & Peet 2003). The theory that birds use ultrasound to avoid noise masking was discarded when it was discovered that there was no corresponding auditory brainstem response (i.e. sensory perception) to the ultrasonic calls in the hummingbirds producing those calls.

Wing morphology, echolocation calls, diet and emergence time of black-bearded tomb bats (Taphozous melanopogon, Emballonuridae) from southwest China

We studied the wing morphology, echolocation calls, diet and emergence time of the black-bearded tomb bat (Taphozous melanopogon) from May to October 2006 in Guangxi Province, southwest China. Taphozous melanopogon has wings with high aspect ratio, high loading and pointed wing-tip shape-characteristics associated with fast flight in open space. This species usually produces low-intensity, low frequency, and frequency-modulated (FM) calls usually containing up to four harmonics, with most energy in the second (or sometimes third) harmonic. The diet of this species consists mostly of Lepidoptera and Hemiptera. Timing of evening emergence is correlated with the time of sunset. This is the first study to describe the flight and echolocation behavior of this species in China, and opens the way for future studies of its biology.

Effects of different surfaces on the perception of prey-generated noise by the Indian false vampire bat Megaderma lyra.

The low- and high-frequency components of a rustling sound, created when prey (freshly killed frog) was jerkily pulled on dry and wet sandy floors and asbestos, were recorded and played back to individual Indian false vampire bats (Megaderma lyra). Megaderma lyra responded with flight toward the speakers and captured dead frogs, that were kept as reward. The spectral peaks were at 8.6, 7.1 and 6.8 kHz for the low-frequency components of the sounds created at the dry, asbestos and wet floors, respectively. The spectral peaks for the high-frequency sounds created on the respective floors were at 36.8,27.2 and 23.3 kHz. The sound from the dry floor was more intense than that of from the other two substrata. Prey movements that generated sonic or ultrasonic sounds were both sufficient and necessary for the bats to detect and capture prey. The number of successful prey captures was significantly greater for the dry floor sound, especially to its high-frequency components. Bat-responses were low to the wet floor and moderate to the asbestos floor sounds. The bats did not respond to the sound of unrecorded parts of the tape. Even though the bats flew toward the speakers when the prey generated sounds were played back and captured the dead frogs we cannot rule out the possibility of M. lyra using echolocation to localize prey. However, the study indicates that prey that move on dry sandy floor are more vulnerable to predation by M. lyra.

The use of a Riesz fractional differential-based approach for texture enhancement in image processing

Texture enhancement is an important component of image processing that finds extensive application in science and engineering. The quality of medical images, quantified using the imaging texture, plays a significant role in the routine diagnosis performed by medical practitioners. Most image texture enhancement is performed using classical integral order differential mask operators. Recently, first order fractional differential operators were used to enhance images. Experimentation with these methods led to the conclusion that fractional differential operators not only maintain the low frequency contour features in the smooth areas of the image, but they also nonlinearly enhance edges and textures corresponding to high frequency image components. However, whilst these methods perform well in particular cases, they are not routinely useful across all applications. To this end, we apply the second order Riesz fractional differential operator to improve upon existing approaches of texture enhancement. Compared with the classical integral order differential mask operators and other first order fractional differential operators, we find that our new algorithms provide higher signal to noise values and superior image quality.

Development of a cost-effective and flexible vibration DAQ system for long-term continuous structural health monitoring

In the structural health monitoring (SHM) field, long-term continuous vibration-based monitoring is becoming increasingly popular as this could keep track of the health status of structures during their service lives. However, implementing such a system is not always feasible due to on-going conflicts between budget constraints and the need of sophisticated systems to monitor real-world structures under their demanding in-service conditions. To address this problem, this paper presents a comprehensive development of a cost-effective and flexible vibration DAQ system for long-term continuous SHM of a newly constructed institutional complex with a special focus on the main building. First, selections of sensor type and sensor positions are scrutinized to overcome adversities such as low-frequency and low-level vibration measurements. In order to economically tackle the sparse measurement problem, a cost-optimized Ethernet-based peripheral DAQ model is first adopted to form the system skeleton. A combination of a high-resolution timing coordination method based on the TCP/IP command communication medium and a periodic system resynchronization strategy is then proposed to synchronize data from multiple distributed DAQ units. The results of both experimental evaluations and experimental–numerical verifications show that the proposed DAQ system in general and the data synchronization solution in particular work well and they can provide a promising cost-effective and flexible alternative for use in real-world SHM projects. Finally, the paper demonstrates simple but effective ways to make use of the developed monitoring system for long-term continuous structural health evaluation as well as to use the instrumented building herein as a multi-purpose benchmark structure for studying not only practical SHM problems but also synchronization related issues.

A functional MRI study of the relationship between naming treatment outcomes and resting state functional connectivity in post-stroke aphasia

Background: The majority of studies investigating the neural mechanisms underlying treatment in people with aphasia have examined task-based brain activity. However, the use of resting-state fMRI may provide another method of examining the brain mechanisms responsible for treatment-induced recovery, and allows for investigation into connectivity within complex functional networks Methods: Eight people with aphasia underwent 12 treatment sessions that aimed to improve object naming. Half the sessions employed a phonologically-based task, and half the sessions employed a semantic-based task, with resting-state fMRI conducted pre- and post-treatment. Brain regions in which the amplitude of low frequency fluctuations (ALFF) correlated with treatment outcomes were used as seeds for functional connectivity (FC) analysis. FC maps were compared from pre- to post-treatment, as well as with a group of 12 healthy older controls Results: Pre-treatment ALFF in the right middle temporal gyrus (MTG) correlated with greater outcomes for the phonological treatment, with a shift to the left MTG and supramarginal gyrus, as well as the right inferior frontal gyrus, post-treatment. When compared to controls, participants with aphasia showed both normalization and up-regulation of connectivity within language networks post-treatment, predominantly in the left hemisphere Conclusions: The results provide preliminary evidence that treatments for naming impairments affect the FC of language networks, and may aid in understanding the neural mechanisms underlying the rehabilitation of language post-stroke.

Development of a switch mode assisted linear amplifier for use as a high fidelity voltage source

Frequency Domain Spectroscopy (FDS) is one of the major techniques used for determining the condition of the cellulose based paper and pressboard components in large oil/paper insulated power transformers. This technique typically makes use of a sinusoidal voltage source swept from 0.1 mHz to 1 kHz. The excitation test voltage source used must meet certain characteristics, such as high output voltage, high fidelity, low noise and low harmonic content. The amplifier used; in the test voltage source; must be able to drive highly capacitive loads. This paper proposes that a switch-mode assisted linear amplifier (SMALA) can be used in the test voltage source to meet these criteria. A three level SMALA prototype amplifier was built to experimentally demonstrate the effectiveness of this proposal. The developed SMALA prototype shows no discernable harmonic distortion in the output voltage waveform, or the need for output filters, and is therefore seen as a preferable option to pulse width modulated digital amplifiers. The lack of harmonic distortion and high frequency switching noise in the output voltage of this SMALA prototype demonstrates its feasibility for applications in FDS, particularly on highly capacitive test objects such as transformer insulation systems.

Omission of author name in the article by Davidson et al (Arthritis Rheum, July 2013)

This article corrects: Brief Report: High-Throughput Sequencing of IL23R Reveals a Low-Frequency, Nonsynonymous Single-Nucleotide Polymorphism That Is Associated With Ankylosing Spondylitis in a Han Chinese Population Vol. 65, Issue 7, 1747–1752, Article first published online: 2 JUL 2013

Burnout and work engagement in occupational therapists

Introduction Work engagement, characterized by vigour, dedication, and absorption, is often perceived as the opposite of burnout. Occupational therapists with burnout feel exhausted and disengaged from their work. This study aims to investigate demographic and work-related psychosocial factors associated with burnout and work engagement. Method A cross-sectional postal survey of 951 occupational therapists was conducted. Findings Two models representing factors associated with burnout (F(15,871) = 28.01, p < .001) and work engagement (F(10,852) = 16.15, p < .001) accounted for 32.54% and 15.93% of the variance respectively. Burnout and work engagement were inversely associated (χ2(n = 941) = 55.16, p < .001). Conclusion Factors associated with burnout and work engagement were identified. The variables associated with burnout included: low psychological detachment from work during out-of-work hours, low income satisfaction, perceived work overload, difficulty saying ‘no’, < 10 years' experience, low frequency of having a ‘belly laugh’, and not having children. High levels of work engagement were reported by therapists with the following: low psychological detachment from work, high income satisfaction, postgraduate qualifications, > 40 hours work/week, high frequency of having a ‘belly laugh’, and having children. Understanding the factors associated with burnout and work engagement provides prerequisite information to inform strategies aimed at building healthy workforces.

Power system stability implications from electromechanical wave propagation

Electromechanical wave propagation characterizes the first-swing dynamic response in a spatially delayed manner. This paper investigates the characteristics of this phenomenon in two-dimensional and one-dimensional power systems. In 2-D systems, the wave front expands as a ripple in a pond. In 1-D systems, the wave front is more concentrated, retains most of its magnitude, and travels like a pulse on a string. This large wave front is more impactful upon any weak link and easily causes transient instability in 1-D systems. The initial disturbance injects both high and low frequency components, but the lumped nature of realistic systems only permits the lower frequency components to propagate through. The kinetic energy split at a junction is equal to the generator inertia ratio in each branch in an idealized continuum system. This prediction is approximately valid in a realistic power system. These insights can enhance understanding and control of the traveling waves.

Framing as status or benefits? Consumers’ reactions to hierarchical loyalty program communication

Purpose A fundamental aspect of hierarchical loyalty programs is that some consumers get rewards that others do not. Despite the widespread use of such programs, academics have long debated whether these benefits are outweighed by the potential negative impact of the differential treatment of customers. This study extends our understanding, examining the impact of message framing on consumers’ reactions to hierarchical loyalty structures. Design/methodology/approach Three online studies were conducted. Study 1 uses advertisements to manipulate the message frame’s emphasis (benefits vs. status). Study 2 manipulates consumers’ frame of thought by directing their attention to either changes in benefits or status. Finally, Study 3 uses the proposed framework to reconcile contradictory findings from past research. Findings Low-frequency customers who do not expect to qualify for a superior customer tier tend to reject hierarchical programs when thinking about status. In contrast, when these customers think about concrete rewards, loyalty program messages produce no negative reactions. High-frequency customers are positively affected by communication regardless of the type of benefits framed. Research limitations/implications All studies were done online potentially limiting the external validity of the results. Nevertheless, the impact of message framing on perceptions about the loyalty program seems to be quite robust across different studies and manipulations. Practical implications When communicating with low-frequency customers managers should avoid promising status; customers should instead be motivated based on concrete rewards. High-frequency customers are indifferent to alternative emphasis of communication frames. Originality/value Marketing academics have acknowledged the importance of being able to reward top customers without demotivating light and moderate users. Our research is the first to provide a solution to this issue.

The genetic associations of acute anterior uveitis and their overlap with the genetics of ankylosing spondylitis

Acute anterior uveitis (AAU) involves inflammation of the iris and ciliary body of the eye. It occurs both in isolation and as a complication of ankylosing spondylitis (AS). It is strongly associated with HLA-B*27, but previous studies have suggested that further genetic factors may confer additional risk. We sought to investigate this using the Illumina Exomechip microarray, to compare 1504 cases with AS and AAU, 1805 with AS but no AAU and 21 133 healthy controls. We also used a heterogeneity test to test the differences in effect size between AS with AAU and AS without AAU. In the analysis comparing AS+AAU+ cases versus controls, HLA-B*27 and HLA-A*02:01 were significantly associated with the presence of AAU (P<10−300 and P=6 × 10−8, respectively). Secondary independent association with PSORS1C3 (P=4.7 × 10−5) and TAP2 (P=1.1 × 10−5) were observed in the major histocompatibility complex. There was a new suggestive association with a low-frequency variant at zinc-finger protein 154 in the AS without AAU versus control analysis (zinc-finger protein 154 (ZNF154), P=2.2 × 10−6). Heterogeneity testing showed that rs30187 in ERAP1 has a larger effect on AAU compared with that in AS alone. These findings also suggest that variants in ERAP1 have a differential impact on the risk of AAU when compared with AS, and hence the genetic risk for AAU differs from AS.

Whole-genome sequencing identifies EN1 as a determinant of bone density and fracture

The extent to which low-frequency (minor allele frequency (MAF) between 1-5%) and rare (MAF low-frequency non-coding variant near a novel locus, EN1, with an effect size fourfold larger than the mean of previously reported common variants for lumbar spine BMD (rs11692564(T), MAF = 1.6%, replication effect size = +0.20 s.d., Pmeta = 2 x 10(-14)), which was also associated with a decreased risk of fracture (odds ratio = 0.85; P = 2 x 10(-11); ncases = 98,742 and ncontrols = 409,511). Using an En1(cre/flox) mouse model, we observed that conditional loss of En1 results in low bone mass, probably as a consequence of high bone turnover. We also identified a novel low-frequency non-coding variant with large effects on BMD near WNT16 (rs148771817(T), MAF = 1.2%, replication effect size = +0.41 s.d., Pmeta = 1 x 10(-11)). In general, there was an excess of association signals arising from deleterious coding and conserved non-coding variants. These findings provide evidence that low-frequency non-coding variants have large effects on BMD and fracture, thereby providing rationale for whole-genome sequencing and improved imputation reference panels to study the genetic architecture of complex traits and disease in the general population.