Structures of riboswitch RNA reaction states by mix-and-inject XFEL serial crystallography.

Riboswitches are structural RNA elements that are generally located in the 5' untranslated region of messenger RNA. During regulation of gene expression, ligand binding to the aptamer domain of a riboswitch triggers a signal to the downstream expression platform. A complete understanding of the structural basis of this mechanism requires the ability to study structural changes over time. Here we use femtosecond X-ray free electron laser (XFEL) pulses to obtain structural measurements from crystals so small that diffusion of a ligand can be timed to initiate a reaction before diffraction. We demonstrate this approach by determining four structures of the adenine riboswitch aptamer domain during the course of a reaction, involving two unbound apo structures, one ligand-bound intermediate, and the final ligand-bound conformation. These structures support a reaction mechanism model with at least four states and illustrate the structural basis of signal transmission. The three-way junction and the P1 switch helix of the two apo conformers are notably different from those in the ligand-bound conformation. Our time-resolved crystallographic measurements with a 10-second delay captured the structure of an intermediate with changes in the binding pocket that accommodate the ligand. With at least a 10-minute delay, the RNA molecules were fully converted to the ligand-bound state, in which the substantial conformational changes resulted in conversion of the space group. Such notable changes in crystallo highlight the important opportunities that micro- and nanocrystals may offer in these and similar time-resolved diffraction studies. Together, these results demonstrate the potential of 'mix-and-inject' time-resolved serial crystallography to study biochemically important interactions between biomacromolecules and ligands, including those that involve large conformational changes.

Cognitive behavioral therapy for menopausal symptoms.

This article describes cognitive behavioral therapy (CBT) for women with problematic menopausal symptoms, and provides the evidence from clinical trials of women going through the menopause, women with breast cancer treatment-induced symptoms and women with problematic symptoms in a work context. The CBT focus is primarily on vasomotor symptoms (VMS) but it also targets stress, low mood and sleep problems. CBT is a brief therapy (four to six sessions) that is theory- and evidence-based; it is acceptable to women and effectively reduces the impact of VMS, improves sleep and has benefits to quality of life. VMS frequency is also reduced significantly in some trials but not others. CBT has been found to be consistently effective when delivered in groups, self-help book and on-line formats (with or without additional support). The MENOS 1 and MENOS 2 CBT protocols are recommended for the treatment of VMS by the North American Menopause Society (2015); CBT has been recommended for the treatment of anxiety and depression for women during the menopause transition and post menopause (NICE, 2015); and telephone CBT has been shown to be an effective treatment for insomnia.

Variation in menopausal vasomotor symptoms outcomes in clinical trials: a systematic review.

BACKGROUND: There is substantial variation in how menopausal vasomotor symptoms are reported and measured among intervention studies. This has prevented meaningful comparisons between treatments and limited data synthesis. OBJECTIVES: To review systematically the outcome reporting and measures used to assess menopausal vasomotor symptoms from randomised controlled trials of treatments. SEARCH STRATEGY: We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials from inception to May 2018. SELECTION CRITERIA: Randomised controlled trials with a primary outcome of menopausal vasomotor symptoms in women and a sample size of at least 20 women per study arm. DATA COLLECTION AND ANALYSIS: Data about study characteristics, primary vasomotor-related outcomes and methods of measuring them. MAIN RESULTS: The search identified 5591 studies, 214 of which were included. Forty-nine different primary reported outcomes were identified for vasomotor symptoms and 16 different tools had been used to measure these outcomes. The most commonly reported outcomes were frequency (97/214), severity (116/214), and intensity (28/114) of vasomotor symptoms or a composite of these outcomes (68/214). There was little consistency in how the frequency and severity/intensity of vasomotor symptoms were defined. CONCLUSIONS: There is substantial variation in how menopausal vasomotor symptoms have been reported and measured in treatment trials. Future studies should include standardised outcome measures which reflect the priorities of patients, clinicians, and researchers. This is most effectively achieved through the development of a Core Outcome Set. This systematic review is the first step towards development of a Core Outcome Set for menopausal vasomotor symptoms. TWEETABLE SUMMARY: Menopausal hot flushes and night sweats have been reported in 49 different ways in clinical research. A core outcome set is urgently required.

A comparison of three outcome measures of the impact of vasomotor symptoms on women's lives.

Objective: Measures of the impact of vasomotor symptoms (VMS) have been used as outcomes in clinical trials but have not been compared. This study compares the Hot Flush Rating Scale (HFRS), the Hot Flash Related Daily Interference Scale (HFRDIS), and the shorter Hot Flash Interference (HFI) scale. Methods: Baseline data were taken from two studies including healthy women (menopause transition or postmenopause) and breast cancer patients experiencing VMS. Participants completed questionnaires on sociodemographics, the HFRS, the HFRDIS, the HFI, the Work and Social Adjustment Scale (WSAS), on depression (Generalized Anxiety Disorder 7), on anxiety (Patient Health Questionnaire 9), and on use of medical services. Results: A total of 169 women (129 with history of breast cancer and 40 without) aged 54.47 (standard deviation [SD] = 9.11) years took part. They had an average of 66 (SD = 40.94) VMS per week, with a mean HFRS problem-rating of 6.53 (SD = 1.99), HFRDIS score of 5.36 (SD = 2.22), and HFI score of 6.13 (SD = 2.30). The HFRS problem-rating, HFRDIS, and HFI were significantly associated (r = 0.61-0.85), had good internal reliability (α = 0.76-0.91), and had significant concurrent validity with mood, the WSAS, and use of medical services. VMS frequency was not associated with mood, the WSAS, or use of medical services. Conclusion: The HFRS problem-rating scale and the HFI are two brief, three-item measures that measure a similar concept of VMS interference/impact, with evidence of reliability and validity.

Effects and moderators of psychosocial interventions on quality of life, and emotional and social function in patients with cancer: An individual patient data meta-analysis of 22 RCTs.

OBJECTIVE: This individual patient data (IPD) meta-analysis aimed to evaluate the effects of psychosocial interventions (PSI) on quality of life (QoL), emotional function (EF), and social function (SF) in patients with cancer, and to study moderator effects of demographic, clinical, personal, and intervention-related characteristics. METHODS: Relevant studies were identified via literature searches in 4 databases. We pooled IPD from 22 (n = 4217) of 61 eligible randomized controlled trials. Linear mixed-effect model analyses were used to study intervention effects on the post-intervention values of QoL, EF, and SF (z-scores), adjusting for baseline values, age, and cancer type. We studied moderator effects by testing interactions with the intervention for demographic, clinical, personal, and intervention-related characteristics, and conducted subsequent stratified analyses for significant moderator variables. RESULTS: PSI significantly improved QoL (ß = 0.14,95%CI = 0.06;0.21), EF (ß = 0.13,95%CI = 0.05;0.20), and SF (ß = 0.10,95%CI = 0.03;0.18). Significant differences in effects of different types of PSI were found, with largest effects of psychotherapy. The effects of coping skills training were moderated by age, treatment type, and targeted interventions. Effects of psychotherapy on EF may be moderated by cancer type, but these analyses were based on 2 randomized controlled trials with small sample sizes of some cancer types. CONCLUSIONS: PSI significantly improved QoL, EF, and SF, with small overall effects. However, the effects differed by several demographic, clinical, personal, and intervention-related characteristics. Our study highlights the beneficial effects of coping skills training in patients treated with chemotherapy, the importance of targeted interventions, and the need of developing interventions tailored to the specific needs of elderly patients.

Fractal morphology, imaging and mass spectrometry of single aerosol particles in flight.

The morphology of micrometre-size particulate matter is of critical importance in fields ranging from toxicology to climate science, yet these properties are surprisingly difficult to measure in the particles' native environment. Electron microscopy requires collection of particles on a substrate; visible light scattering provides insufficient resolution; and X-ray synchrotron studies have been limited to ensembles of particles. Here we demonstrate an in situ method for imaging individual sub-micrometre particles to nanometre resolution in their native environment, using intense, coherent X-ray pulses from the Linac Coherent Light Source free-electron laser. We introduced individual aerosol particles into the pulsed X-ray beam, which is sufficiently intense that diffraction from individual particles can be measured for morphological analysis. At the same time, ion fragments ejected from the beam were analysed using mass spectrometry, to determine the composition of single aerosol particles. Our results show the extent of internal dilation symmetry of individual soot particles subject to non-equilibrium aggregation, and the surprisingly large variability in their fractal dimensions. More broadly, our methods can be extended to resolve both static and dynamic morphology of general ensembles of disordered particles. Such general morphology has implications in topics such as solvent accessibilities in proteins, vibrational energy transfer by the hydrodynamic interaction of amino acids, and large-scale production of nanoscale structures by flame synthesis.

Menopause and work: an overview of UK guidance.

BACKGROUND: Recent evidence suggests that some women experience menopausal symptoms that impact on their working lives, and that work environments can impact upon the experience of menopause. As a result, guidance for employers and other key stakeholders about this potential occupational health issue has emerged. To date there has not been a review of these documents to identify their main recommendations for policy and practice. AIMS: To provide a narrative overview of such guidance and summary of content. METHODS: Documents published in the UK and available in a major UK trade union library were searched systematically to identify guidance on the topic of menopause and work. An inductive thematic analysis was performed to identify the main themes addressed. RESULTS: Twenty-five relevant documents, on average eight pages long, were identified. A minority indicated that the use of scientific evidence informed the content. Five overarching themes were identified: (i) legislation; (ii) policy; (iii) information and training needs; (iv) workplace support; and (v) the physical work environment. CONCLUSIONS: This overview of UK guidance revealed common areas of concern about reducing and managing difficulties experienced by working menopausal women. Possible areas for action were identified. Some recommendations were common across much of the guidance, whereas others were exclusive. Future guidance might include consideration of all these issues, while making reference both to the evidence base and sources of further information.

Host nuclear genotype influences phenotype of a conditional mutualist symbiont.

Arthropods commonly carry maternally inherited intracellular bacterial symbionts that may profoundly influence host biology and evolution. The intracellular symbiont Rickettsia sp. nr. bellii swept rapidly into populations of the sweetpotato whitefly Bemisia tabaci in the south-western USA. Previous laboratory experiments showed female-bias and fitness benefits were associated with Rickettsia infection, potentially explaining the high frequencies of infection observed in field populations, but the effects varied with whitefly genetic line. Here, we explored whether host extranuclear or nuclear genes influenced the variation in the Rickettsia-host phenotype in two genetic lines of the whitefly host, each with Rickettsia-infected and uninfected sublines. Introgression between the Rickettsia-infected subline of one genetic line and the Rickettsia-uninfected subline of the other was used to create two new sublines, each with the maternally inherited extranuclear genetic lineages of one line (Rickettsia, two other symbionts and the mitochondria) and the nuclear genotype of the other. Performance assays comparing the original and new lines showed that in addition to Rickettsia, the interaction of Rickettsia infection with host nuclear genotype influenced development time and the sex ratio of the progeny, whereas the extranuclear genotype did not. Host nuclear genotype, but not extranuclear genotype, also influenced the titre of Rickettsia. Our results support the hypothesis that differences in host nuclear genotype alone may explain considerable within-population variation in host-symbiont phenotype and may contribute to the observed variation in Rickettsia-whitefly interactions worldwide.

Reproductive interference and fecundity affect competitive interactions of sibling species with low mating barriers: experimental and theoretical evidence.

When allopatric species with incomplete prezygotic isolation come into secondary contact, the outcome of their interaction is not easily predicted. The parasitoid wasp Encarsia suzannae (iES), infected by Cardinium inducing cytoplasmic incompatibility (CI), and its sibling species E. gennaroi (EG), not infected by bacterial endosymbionts, may have diverged because of the complementary action of CI and asymmetric hybrid incompatibilities. Whereas postzygotic isolation is now complete because of sterility of F1 hybrid progeny, prezygotic isolation is still incipient. We set up laboratory population cage experiments to evaluate the outcome of the interaction between ES and EG in two pairwise combinations: iES vs EG and cured ES (cES, where Cardinium was removed with antibiotics) vs EG. We also built a theoretical model aimed at exploring the role of life-history differences and asymmetric mating on competitive outcomes. In three of four cages in each treatment, ES dominated the interaction. We found evidence for reproductive interference, driven by asymmetric mating preferences, that gave a competitive edge to ES, the species that better discriminated against heterospecifics. However, we did not find the fecundity cost previously shown to be associated with Cardinium infection in iES. The model largely supported the experimental results. The finding of only a slight competitive edge of ES over EG in population cages suggests that in a more heterogeneous environment the species could coexist. This is supported by evidence that the two species coexist in sympatry, where preliminary data suggest reproductive character displacement may have reinforced postzygotic isolation.

The menopausal hot flush: a review.

The hot flush is the most characteristic and often the most distressing symptom of the menopause. It is a unique feature and yet the mechanism and health implications are still not fully understood. This review summarizes some of the current thoughts on factors contributing to flushing, the physiological, vascular and neuroendocrine changes associated with flushing and the possible cardiovascular and other health implications for women experiencing hot flushes. Therapy is not discussed.

An International Menopause Society study of vasomotor symptoms in Bangkok and Chiang Mai, Thailand.

OBJECTIVES: To examine relationships between location, demographics, lifestyle, beliefs, and experience of hot flushes and night sweats (HFNS) amongst women living in two cities in Thailand. METHODS: Cross-sectional study of peri- and postmenopausal women, aged 45-55 years, from Bangkok and Chiang Mai. Participants completed questionnaires (demographics, health, HFNS (prevalence, frequency and problem-rating) and beliefs about menopause). A sub-sample of women from each location was interviewed. RESULTS: A total of 632 women (320 Bangkok and 312 Chiang Mai) aged 50.88 (standard deviation 3.06) years, took part. The prevalence of HFNS was 65%, average HFNS frequency 8.7 (10.8) per week and problem rating 4.3/10. Women from Chiang Mai had significantly more problematic HFNS, but prevalence and frequency were similar in both sites. Poor general health predicted HFNS prevalence and frequency, while Chiang Mai location, HFNS frequency, age, diet and beliefs about menopause were associated with problematic HFNS. Location remained significant after controlling for education, occupation and age; location was partially explained by beliefs. Qualitative interview responses illustrated the differences in beliefs about menopause between locations. CONCLUSION: HFNS reports are prevalent with moderate frequency and problem-ratings in these urban centers in Thailand. The results will be included in the broader International Menopause Society study of Climate, Altitude and Temperature (IMS-CAT) of the impact of climate on HFNS.

Prevalence and predictors of complementary and alternative medicine/non-pharmacological interventions use for menopausal symptoms within the UK Collaborative Trial of Ovarian Cancer Screening.

OBJECTIVES: The negative publicity about menopausal hormone therapy (MHT) has led to increased use of complementary and alternative medicines (CAM) and non-pharmacological interventions (NPI) for menopausal symptom relief. We report on the prevalence and predictors of CAM/NPI among UK postmenopausal women. METHOD: Postmenopausal women aged 50-74 years were invited to participate in the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS). A total of 202 638 women were recruited and completed a baseline questionnaire. Of these, 136 020 were sent a postal follow-up-questionnaire between September 2006 and May 2009 which included ever-use of CAM/NPI for menopausal symptom relief. Both questionnaires included MHT use. RESULTS: A total of 88 430 (65.0%) women returned a completed follow-up-questionnaire; 22 206 (25.1%) reported ever-use of one or more CAM/NPI. Highest use was reported for herbal therapies (43.8%; 9725/22 206), vitamins (42.6%; 9458/22 206), lifestyle approaches (32.1%; 7137/22 206) and phytoestrogens (21.6%; 4802/22 206). Older women reported less ever-use of herbal therapies, vitamins and phytoestrogens. Lifestyle approaches, aromatherapy/reflexology/acupuncture and homeopathy were similar across age groups. Higher education, Black ethnicity, MHT or previous oral contraceptive pill use were associated with higher CAM/NPI use. Women assessed as being less hopeful about their future were less likely to use CAM/NPI. CONCLUSION: One in four postmenopausal women reported ever-use of CAM therapies/NPI for menopausal symptom relief, with lower use reported by older women. Higher levels of education and previous MHT use were positive predictors of CAM/NPI use. UKCTOCS Trial registration: ISRCTN22488978.

Measuring depression in prostate cancer patients: does the scale used make a difference?

This study investigated differences in the scores, relative severity and major depressive disorder (MDD) and subsyndromal depression status from three standardised self-report scales for depression in prostate cancer (PCa) patients. The Hospital Anxiety and Depression Scale Depression subscale (HADS-D), the Self-rating Depression Scale (SDS) and the Patient Health Questionnaire (PHQ-9) for depression were administered to a sample of 138 PCa patients via mail-out self-reports in Queensland, Australia during May 2014. Despite significant correlations between the total scores from the three scales, severity classification differed across the three scales and there was evidence of considerable underestimation of depression by the HADS-D compared to the PHQ-9, and a similar tendency for the SDS. When patients were classified as fulfilling the criteria for Subsyndromal Depression on the PHQ-9, there were statistically significant differences in the proportion of patients who met those criteria using the HADS-D and the SDS, with large underestimation also present for these two scales. Scale construction and depression items included can produce different results across scales, making inter-study comparisons difficult. Implications for research and clinical practice are described.

Men's experience of a guided self-help intervention for hot flushes associated with prostate cancer treatment.

Up to 80% of men who receive androgen deprivation therapy report hot flushes and for many these are associated with reduced quality of life. However it is recognised that there are a number of barriers to men's engagement with support to manage symptoms and improve quality of life. This qualitative study was embedded within a larger randomised controlled trial (MANCAN) of a guided self-help cognitive behavioural intervention to manage hot flushes resulting among men receiving androgen deprivation therapy. The study aimed to explore the engagement and experiences with the guided self-help intervention. Twenty men recruited from the treatment arm of the MANCAN trial participated in a semi-structured interview exploring acceptability of the intervention, factors affecting engagement and perceived usefulness of the intervention. Interviews were audio-recorded, transcribed verbatim and analysed using a Framework approach. Over two thirds of respondents (69%) reported reading the intervention booklet in full and over 90% reporting practising the relaxation CD at least once a week. Analysis of the interviews identified three super-ordinate themes and these related to changes in hot flush symptomatology (learned to cope with hot flushes in new ways), the skills that participants had derived from the intervention (promoting relaxation and reducing stressors), and to a broader usefulness of the intervention (broader impact of the intervention and skills). The present study identified positive engagement with a guided self-help intervention and that men applied the skills developed through the intervention to help them undertake general lifestyle changes. Psycho-educational interventions (e.g. cognitive behaviour therapy, relaxation, and positive lifestyle elements) offer the potential to be both effective and well received by male cancer survivors.

Barriers to medical help-seeking among older men with prostate cancer.

OBJECTIVE: Men's disinclination to seek medical help has been linked to higher rates of morbidity and mortality compared to women. However, previous studies were conducted predominantly with healthy, young, and middle-aged men. We explored the perceived medical barriers to help-seeking in older men with prostate cancer. METHOD: 20 men with prostate cancer took part in semistructured interviews, which were analyzed using thematic analysis. RESULTS: Three themes were identified related to negative attitudes toward help-seeking: male gender role; fear of the health condition, medical and treatment procedures; and embarrassment as a consequence of medical examinations, communication with health (and nonhealth) professionals, and the disclosure of sexual-related symptoms. CONCLUSION: The barriers identified in our study strengthen the evidence for the impact of traditional masculinity on help-seeking in men.

Vasomotor symptoms in prostate cancer survivors undergoing androgen deprivation therapy.

OBJECTIVE: Hot flushes and night sweats (HFNS) are common but under-researched in prostate cancer survivors undergoing androgen-deprivation therapy (ADT). We aimed to examine subjective reports and physiological measures of HFNS, and the influence of sociodemographic, clinical and psychological factors on HFNS in men undergoing ADT. METHODS: Sixty-eight men undergoing ADT for prostate cancer attended an assessment interview, completed questionnaires (assessing HFNS frequency and problem-rating, mood, stress, optimism, somatosensory amplification, HFNS beliefs/behaviors) and wore an ambulatory sternal skin conductance (SSC) monitor for 48 h. RESULTS: The sample had a mean age of 69.76 (standard deviation, SD = 8.04) years, were on average 27.24 (SD = 28.53) months since cancer diagnosis and had been on their current ADT regime for 16 months (range 2-74 months). The men reported frequent (weekly mean 51.04, SD = 33.21) and moderately problematic HFNS. Overall, 294 (20%) of the SSC-defined HFNS were concordant with prospective frequency (event marker), while 63% were under-reported and 17% were over-reported, under-reporting being more common than over-reporting. There were no significant predictors of HFNS frequency (subjective or physiological measures), but psychological variables (HFNS beliefs and behaviors (ß = 0.56, p < 0.03), anxiety (ß = 0.24, p < 0.01) and somatic amplification (ß = 0.76, p < 0.04) were the main predictors of problematic HFNS, i.e. troublesome symptoms. CONCLUSIONS: These results are consistent with those of studies of women during menopause and breast cancer survivors, i.e. subjective and physiological measures appear to identify different HFNS dimensions. Psychological variables (HFNS beliefs and behaviors, anxiety and somatic amplification) can be targeted, using cognitive behavior therapy, for symptom relief.

The effectiveness of exercise as treatment for vasomotor menopausal symptoms: randomised controlled trial.

OBJECTIVE: To investigate the effectiveness of exercise as treatment for vasomotor menopausal symptoms. DESIGN: Three-group randomised controlled trial, two exercise interventions and a control group. SETTING: Primary Care, West Midlands UK. POPULATION: Perimenopausal and postmenopausal women experiencing at least five hot flushes/night sweats per day and not taken MHT in previous 3 months were recruited from 23 general practices. METHODS: Participants in both exercise interventions groups were offered two face-to-face consultations with a physical activity facilitator to support engagement in regular exercise. In addition, one exercise group received a menopause-specific information DVD and written materials to encourage regular exercise and the other exercise group was offered the opportunity to attend exercise social support groups in their communities. Interventions lasted 6 months. MAIN OUTCOME MEASURE: The primary outcome was frequency of hot flushes/night sweats at 6-month up. RESULTS: Two hundred and sixty-one women were randomised (n = 87 per group). Neither of the exercise intervention groups reported significantly less frequent hot flushes/night sweats per week than controls (exercise-DVD versus control: -8.9, 95% CI -20.0 to 2.2; exercise-social support versus control: -5.2, 95% CI -16.7 to 6.3). CONCLUSIONS: This trial indicates that exercise is not an effective treatment for hot flushes/night sweats. Contrary to current clinical guidance, women should not be advised that exercise will relieve their vasomotor menopausal symptoms.

A multidisciplinary, biopsychosocial treatment for non-cardiac chest pain.

BACKGROUND: Non-cardiac chest pain (NCCP) affects up to 80% of patients attending chest pain clinics, but its treatment is suboptimal. AIM: To describe the outcomes of a pilot, stepped care, biopsychosocial management programme in terms of improvements in chest pain, psychosocial scores and use of healthcare resources. METHODS: Of 198 referrals, 77 patients were suitable for the clinic and received a one hour biopsychosocial assessment. Stepped care consisted of assessment only, low intensity Cognitive Behaviour Therapy (CBT), or high intensity CBT. RESULTS: The proportion with pain occurring more than once monthly fell from 100% at baseline to 61% at 3 months (p < 0.001). Pain interference reduced significantly (p < 0.001) from 5.9 [SD 2.2] at baseline to 3.2 [SD 2.6] at 3 months. Depression scores improved from a mean 8.8 to 5.4 (p < 0.05) and anxiety from 6.9 to 4.6 (p < 0.05). Use of healthcare resources improved with a fall in consultations for chest pain over 6 months from a mean 2.6 to 0.1 (p < 0.05). The impact on work and social functioning reduced from 10.4 [SD 10.4] to 3.9 [SD 7.5]: [t (70) = 6.3, p < 0.001). Further improvements occurred at 6 months for chest pain frequency (which fell to 51%, p = 0.003), interference (2.6 [SD 2.1], p < 0.05) and avoidance of exercise (p = 0.03). Otherwise improvements were maintained between 3 and 6 months. CONCLUSION: A stepped-care biopsychosocial approach to NCCP is effective in reducing chest pain frequency and improving behaviour and wellbeing. It can be delivered in part by a nurse allowing integration into any chest pain clinic.

Egg and time limitation mediate an egg protection strategy.

The number of mature eggs remaining in the ovaries and the time left for oviposition determine the reproductive decisions of the hyperdiverse guild of insects that require discrete and potentially limiting resources for oviposition (such as seeds, fruits or other insects). A female may run out of eggs before all available oviposition sites are used (egg limitation), or die before using all of her eggs (time limitation). Females are predicted to change clutch size depending on whether eggs or time is the limiting resource. We extend this framework and ask whether the same constraints influence a strategy in which females modify eggs into protective shields. In response to egg parasitism cues, female seed beetles (Mimosestes amicus) lay eggs in vertical groups of 2-4, modifying the top 1-3 eggs into shields in order to protect the bottom egg from attack by parasitoids. We made contrasting predictions of how egg and time limitation would influence egg size and the incidence and level of egg protection. By varying access to seed pods, we manipulated the number of remaining eggs a female had at the time she received a parasitism cue. Although egg size was not affected, our results confirm that egg-limited females protected fewer eggs and time-limited females protected more eggs. Female body size explained the number of eggs in a stack rather than host deprivation or the timing of parasitoid exposure. Our results clearly show that host availability relative to female age influences the incidence of egg protection in M. amicus. Furthermore, our study represents a novel use of life history theory to explain patterns in an unusual but compelling defensive behaviour.

The impact of inducing germination of Bacillus anthracis and Bacillus thuringiensis spores on potential secondary decontamination strategies.

AIMS: Decontamination and remediation of a site contaminated by the accidental or intentional release of fully virulent Bacillus anthracis spores are difficult, costly and potentially damaging to the environment. Development of novel decontamination strategies that have minimal environmental impacts remains a high priority. Although ungerminated spores are amongst the most resilient organisms known, once exposed to germinants, the germinating spores, in some cases, become susceptible to antimicrobial environments. We evaluated the concept that once germinated, B. anthracis spores would be less hazardous and significantly easier to remediate than ungerminated dormant spores. METHODS AND RESULTS: Through in vitro germination and sensitivity assays, we demonstrated that upon germination, B. anthracis Ames spores and Bacillus thuringiensis Al Hakam spores (serving as a surrogate for B. anthracis) become susceptible to environmental stressors. The majority of these germinated B. anthracis and B. thuringiensis spores were nonviable after exposure to a defined minimal germination-inducing solution for prolonged periods of time. Additionally, we examined the impact of potential secondary disinfectant strategies including bleach, hydrogen peroxide, formaldehyde and artificial UV-A, UV-B and UV-C radiation, employed after a 60-min germination-induction step. Each secondary disinfectant employs a unique mechanism of killing; as a result, germination-induction strategies are better suited for some secondary disinfectants than others. CONCLUSIONS: These results provide evidence that the deployment of an optimal combination strategy of germination-induction/secondary disinfection may be a promising aspect of wide-area decontamination following a B. anthracis contamination event. SIGNIFICANCE AND IMPACT OF THE STUDY: By inducing spores to germinate, our data confirm that the resulting cells exhibit sensitivities that can be leveraged when paired with certain decontamination measures. This increased susceptibility could be exploited to devise more efficient and safe decontamination measures and may obviate the need for more stringent methods that are currently in place.