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The terminal investment hypothesis proposes that, when individuals are faced with a threat to survival, they will increase investment in current reproduction. The level of the threat necessary to elicit terminal investment (the dynamic terminal investment threshold) may vary based on other factors that also influence future reproduction. Here, we tested whether there is an interactive effect of age and an immune challenge on the dynamic terminal investment threshold in the Pacific field cricket, Teleogryllus oceanicus. We measured the courtship call, mating attractiveness, ejaculate size, and offspring production of T. oceanicus males. We found only limited support for the dynamic terminal investment threshold: there was no consistent evidence of a positive interaction between male age and immune challenge intensity. However, we found evidence for age-related terminal investment: older males produced a larger spermatophore than younger males. Older males also had a slower calling rate compared to younger males, suggesting a potential trade-off between these two pre- and post-copulatory traits. As some, but not all, reproductive traits responded plastically to cues for terminal investment, our research highlights the importance of considering a broad range of pre-and post-copulatory traits when exploring the potential for terminal investment to occur.

Microglia, the resident myeloid cells in the central nervous system (CNS) play critical roles in shaping the brain during development, responding to invading pathogens, and clearing tissue debris or aberrant protein aggregations during ageing and neurodegeneration. The original concept that like macrophages, microglia are either damaging (pro-inflammatory) or regenerative (anti-inflammatory) has been updated to a kaleidoscope view of microglia phenotypes reflecting their wide-ranging roles in maintaining homeostasis in the CNS and, their contribution to CNS diseases, as well as aiding repair. The use of new technologies including single cell/nucleus RNA sequencing has led to the identification of many novel microglia states, allowing for a better understanding of their complexity and distinguishing regional variations in the CNS. This has also revealed differences between species and diseases, and between microglia and other myeloid cells in the CNS. However, most of the data on microglia heterogeneity have been generated on cells isolated from the cortex or whole brain, whereas white matter changes and differences between white and grey matter have been relatively understudied. Considering the importance of microglia in regulating white matter health, we provide a brief update on the current knowledge of microglia heterogeneity in the white matter, how microglia are important for the development of the CNS, and how microglial ageing affects CNS white matter homeostasis. We discuss how microglia are intricately linked to the classical white matter diseases such as multiple sclerosis and genetic white matter diseases, and their putative roles in neurodegenerative diseases in which white matter is also affected. Understanding the wide variety of microglial functions in the white matter may provide the basis for microglial targeted therapies for CNS diseases.

Glioblastoma (GBM) brain tumors contain a subpopulation of self-renewing multipotent Glioblastoma stem-like cells (GSCs) that are believed to drive the near inevitable recurrence of GBM. We previously engineered temperature responsive scaffolds based on the polymer poly(N-isopropylacrylamide-co-Jeffamine M-1000 acrylamide) (PNJ) for the purpose of enriching GSCs in vitro from patient-derived samples. Here, we used PNJ scaffolds to study microenvironmental regulation of self-renewal and radiation response in patient-derived GSCs representing classical and proneural subtypes. GSC self-renewal was regulated by the composition of PNJ scaffolds and varied with cell type. PNJ scaffolds protected against radiation-induced cell death, particularly in conditions that also promoted GSC self-renewal. Additionally, cells cultured in PNJ scaffolds exhibited increased expression of the transcription factor HIF2α, which was not observed in neurosphere culture, providing a potential mechanistic basis for differences in radio-resistance. Differences in PNJ regulation of HIF2α in irradiated and untreated conditions also offered evidence of stem plasticity. These data show PNJ scaffolds provide a unique biomaterial for evaluating dynamic microenvironmental regulation of GSC self-renewal, radioresistance, and stem plasticity.

Myelin is required for the function of neuronal axons in the central nervous system, but the mechanisms that support myelin health are unclear. Although macrophages in the central nervous system have been implicated in myelin health1, it is unknown which macrophage populations are involved and which aspects they influence. Here we show that resident microglia are crucial for the maintenance of myelin health in adulthood in both mice and humans. We demonstrate that microglia are dispensable for developmental myelin ensheathment. However, they are required for subsequent regulation of myelin growth and associated cognitive function, and for preservation of myelin integrity by preventing its degeneration. We show that loss of myelin health due to the absence of microglia is associated with the appearance of a myelinating oligodendrocyte state with altered lipid metabolism. Moreover, this mechanism is regulated through disruption of the TGFβ1–TGFβR1 axis. Our findings highlight microglia as promising therapeutic targets for conditions in which myelin growth and integrity are dysregulated, such as in ageing and neurodegenerative disease2,3.

In recent years, histone deacetylase inhibitors (HDACi) have garnered considerable interest for the treatment of adult and pediatric malignant brain tumors. However, owing to their broad-spectrum nature and inability to effectively penetrate the blood-brain barrier, HDACi have failed to provide significant clinical benefit to glioblastoma (GBM) patients to date. Moreover, global inhibition of HDACs results in widespread toxicity, highlighting the need for selective isoform targeting. While no isoform-specific HDACi are currently available, the second-generation hydroxamic acid-based HDACi quisinostat possesses sub-nanomolar specificity for class I HDAC isoforms, particularly HDAC1 and 2. Recently, we demonstrated that HDAC1 is the essential HDAC in GBM. Here, we provide the first report on the neuro-pharmacokinetic, pharmacodynamic and radiation-sensitizing properties of quisinostat in preclinical models of GBM. We demonstrate that quisinostat is a well-tolerated and brain-penetrant molecule that significantly extends survival when administered in combination with radiationin vivo. The pharmacokinetic-pharmacodynamic-efficacy relationship was established by correlating free drug concentrations and evidence of target modulation in the brain with survival benefit. Together, these data provide a strong rationale for clinical development of quisinostat as a radiosensitizer for the treatment of GBM.

Theoretical models predict that virgin females at risk of not mating should strategically adjust their signalling investment as they age, with older, virgin females investing more to attract males. We explored how adult age influences the ‘calling’ (pheromone-releasing) behaviour of virgin female gumleaf skeletonizer moths, Uraba lugens, over four consecutive 10 h scotophases (dark periods). Adult virgin females commenced calling shortly after the onset of the scotophase. We found that female investment in calling behaviour changed with age: but in contrast with theoretical predictions and empirical observations in other species, older females were less likely to call and spent less time calling than younger females. Older females, however, commenced calling earlier in the scotophase, suggesting that there may be selection on older females to avoid competition from younger conspecific females. We also examined male olfactory preferences for pheromones from females of different ages. Y-maze assays showed that males preferred the pheromones produced by younger females, and that pheromone quality probably plays a role in this choice. Combined, these results suggest that female U. lugens may adaptively adjust their calling behaviour with age to mitigate against the risk of mating failure through competition with other females. The preference of males for pheromones produced by younger females is consistent with this interpretation.

In this issue of Neuron, Chen et al. (2021) reveal dynamic changes in myelin in an Alzheimer's disease (AD) mouse model. Enhancing myelination genetically or pharmacologically improves cognition in this model, supporting myelin as a therapeutic target for AD.

One conspicuous manifestation of sexual conflict is traumatic mating, in which male genitalia damage the female during copulation. The penis of the seed beetle, Callosobruchus maculatus, is covered in spines that damage the female reproductive tract. Females kick males ostensibly to shorten these harmful copulations. How these iconic conflict behaviors coevolve in response to sexual conflict intensity can provide insight into the economics of these traits. We examined whether male harm and female resistance coevolved in response to elevated sexual conflict. We quantified copulation behavior and female reproductive tract damage of individuals from replicated populations evolving for 32 generations under low or high sexual conflict (female- and male-biased treatments, respectively). First, we permitted females ad libitum matings with males from either sex-ratio treatment, recording her tract damage and longevity. Second, we performed a full-factorial cross of matings by males and females from each of the replicate populations, recording mating and kicking duration and reproductive output. We found manipulation of sexual conflict intensity led to the evolution of male harmfulness, but not female resistance to harm. We also demonstrate that female kicking does not respond to sexual conflict intensity, suggesting it does not function to mitigate male harm in this species. Our findings demonstrate the complexities of behavioral and morphological coevolutionary responses to sexual conflict intensity in an important model species.

MS 0735.6+7421 ($z = 0.216$) is a massive cool core galaxy cluster hosting one of the most powerful active galactic nuclei (AGN) outbursts known. The radio jets of the AGN have carved out an unusually large pair of X-ray cavities, each reaching a diameter of $200$ kpc. This makes MS 0735.6+7421 a unique case to investigate active galactic nuclei feedback processes, as well as other cluster astrophysics at radio wavelengths. We present new low-radio-frequency observations of MS 0735.6+7421 taken with the Karl G. Jansky Very Large Array (VLA): 5 hours of P-band ($224-480$ MHz) and 5 hours of L-band ($1-2$ GHz) observations, both in C configuration. Our VLA P-band ($224-480$ MHz) observations reveal the presence of a new diffuse radio component reaching a scale of $\sim$ $900$ kpc in the direction of the jets and of $\sim$ $500$ kpc in the direction perpendicular to the jets. This component is centered on the cluster core and has a radio power scaled at $1.4$ GHz of $P_{1.4\text{ GHz}} = (4\pm2)\times 10^{24}$ WHz$^{-1}$. Its properties are consistent with those expected from a radio mini-halo as seen in other massive cool core clusters, although it may also be associated with radio plasma that has diffused out of the X-ray cavities. Observations at higher spatial resolution are needed to fully characterize the properties and nature of this component. We also suggest that if radio mini-halos originate from jetted activity, we may be witnessing the early stages of this process., Comment: 11 pages, 7 figures, submitted to MNRAS

Microglia, the resident myeloid cells in the central nervous system (CNS) play critical roles in shaping the brain during development, responding to invading pathogens, and clearing tissue debris or aberrant protein aggregations during ageing and neurodegeneration. The original concept that like macrophages, microglia are either damaging (pro-inflammatory) or regenerative (anti-inflammatory) has been updated to a kaleidoscope view of microglia phenotypes reflecting their wide-ranging roles in maintaining homeostasis in the CNS and, their contribution to CNS diseases, as well as aiding repair. The use of new technologies including single cell/nucleus RNA sequencing has led to the identification of many novel microglia states, allowing for a better understanding of their complexity and distinguishing regional variations in the CNS. This has also revealed differences between species and diseases, and between microglia and other myeloid cells in the CNS. However, most of the data on microglia heterogeneity have been generated on cells isolated from the cortex or whole brain, whereas white matter changes and differences between white and grey matter have been relatively understudied. Considering the importance of microglia in regulating white matter health, we provide a brief update on the current knowledge of microglia heterogeneity in the white matter, how microglia are important for the development of the CNS, and how microglial ageing affects CNS white matter homeostasis. We discuss how microglia are intricately linked to the classical white matter diseases such as multiple sclerosis and genetic white matter diseases, and their putative roles in neurodegenerative diseases in which white matter is also affected. Understanding the wide variety of microglial functions in the white matter may provide the basis for microglial targeted therapies for CNS diseases.

Aims To describe laboratory data on clinical human Verotoxigenic E. coli (VTEC) strains causing haemolytic uraemic syndrome (HUS) and to characterise the VTEC strains, thus contributing to risk mitigation to decrease HUS incidence in Ireland. Methods Laboratory characterisation was performed on isolates from 52 VTEC-associated HUS cases identified in the National clinical VTEC Reference Laboratory (NRL-VTEC) for the years 2012-2014. Data were analysed with respect to age, gender, serogroup and verotoxin type and subtype. Results 52/83 (62.6%) culture positive HUS cases were identified from laboratory data; 30 (57.7%) cases occurred in females. Seven HUS-associated serogroups and eleven patterns of verotoxin subtypes are described. Conclusion Ireland has the highest incidence of VTEC infection in Europe and a variety of VTEC serogroups causing clinical infection, suggesting any viable VTEC may potentially cause HUS. A broad diagnostic approach, to detect uncommon serotypes, should be considered when analysing clinical and food samples for VTEC.

Sexually antagonistic coevolution can drive the evolution of male traits that harm females, and female resistance to those traits. While males have been found to vary their harmfulness to females in response to social cues, plasticity in female resistance traits remains to be examined. Here, we ask whether female seed beetles Callosobruchus maculatus are capable of adjusting their resistance to male harm in response to the social environment. Among seed beetles, male genital spines harm females during copulation and females might resist male harm via thickening of the reproductive tract walls. We develop a novel micro computed tomography imaging technique to quantify female reproductive tract thickness in three-dimensional space, and compared the reproductive tracts of females from populations that had evolved under high and low levels of sexual conflict, and for females reared under a social environment that predicted either high or low levels of sexual conflict. We find little evidence to suggest that females can adjust the thickness of their reproductive tracts in response to the social environment. Neither did evolutionary history affect reproductive tract thickness. Nevertheless, our novel methodology was capable of quantifying fine-scale differences in the internal reproductive tracts of individual females, and will allow future investigations into the internal organs of insects and other animals.

Group living can select for increased immunity, given the heightened risk of parasite transmission. Yet, it also may select for increased male reproductive investment, given the elevated risk of female multiple mating. Trade-offs between immunity and reproduction are well documented. Phenotypically, population density mediates both reproductive investment and immune function in the Indian meal moth, Plodia interpunctella. However, the evolutionary response of populations to these traits is unknown. We created two replicated populations of P. interpunctella, reared and mated for 14 generations under high or low population densities. These population densities cause plastic responses in immunity and reproduction: at higher numbers, both sexes invest more in one index of immunity (phenoloxidase (PO) activity) and males invest more in sperm. Interestingly, our data revealed divergence in PO and reproduction in a different direction to previously reported phenotypic responses. Males evolving at low population densities transferred more sperm and both males and females displayed higher PO than individuals at high population densities. These positively correlated responses to selection suggest no apparent evolutionary trade-off between immunity and reproduction. We speculate that the reduced PO activity and sperm investment when evolving under high population density may be due to the reduced population fitness predicted under increased sexual conflict and/or to trade-offs between pre- and post-copulatory traits. This article is protected by copyright. All rights reserved.

The rapid evolutionary divergence of male genital structures under sexual selection is well documented. However, variation in female genital traits and the potential for sexual conflict to drive the coevolution between male and female traits has only recently received attention. In many lepidopterans, females possess genital teeth (collectively, signa). Comparative studies suggest these teeth, involved in the deflation of spermatophores, may have coevolved with male spermatophore thickness via sexually antagonistic coevolution in a contest over the rate of deflation of spermatophores within the reproductive tract. We tested the hypothesis that sexual conflict should generate coevolution between genital teeth and spermatophore morphology by examining these traits under experimental manipulation of sexual conflict intensity. Using micro-CT scanning, we examined spermatophore and teeth morphology in populations of the Indian moth, Plodia interpunctella, which had been evolving for 110 generations under different adult sex-ratio biases. We found divergence in female signa morphology in response to sexual conflict: females from female-biased populations (reduced sexual conflict) developed wider signa. However, we found no evidence of coevolution between signa traits and spermatophore thickness as reported from comparative studies.

Routine electroencephalogram (rEEG) is an important investigation in suspected seizures but can be normal in people with epilepsy. The diagnostic yield of rEEG varies considerably according to the patient group studied. We aimed to estimate the diagnostic yield of rEEG in a real-world cohort of adults with active epilepsy—a population not previously reported. This single centre study evaluated neurophysiology findings for adults with prolonged inpatient video EEG (vEEG)-confirmed active epilepsy, who had at least one prior rEEG. Sixty-eight patients had a total of 171 rEEGs, of which 93 (54.4%) were normal, 42 (24.6%) found non-specific abnormalities and 36 (21.1%) captured interictal epileptiform abnormalities (IIEAs). Serial rEEGs revealed a 22.1% yield of IIEAs on the first test, with the cumulative yield peaking at 33.8% on the fourth rEEG. This study adds to existing evidence regarding the limited diagnostic usefulness of serial rEEG in patients with active epilepsy.

Juvenile population density has profound effects on subsequent adult development, morphology and reproductive investment. Yet, little is known about how the juvenile social environment affects adult investment into chemical sexual signalling. Male gumleaf skeletonizer moths, Uraba lugens, facultatively increase investment into antennae (pheromone receiving structures) when reared at low juvenile population densities, but whether there is comparable adjustment by females into pheromone investment is not known. We investigate how juvenile population density influences the ‘calling' (pheromone-releasing) behaviour of females and the attractiveness of their pheromones. Female U. lugens adjust their calling behaviour in response to socio-sexual cues: adult females reared in high juvenile population densities called earlier and for longer than those from low juvenile densities. Juvenile density also affected female pheromonal attractiveness: Y-maze olfactometer assays revealed that males prefer pheromones produced by females reared at high juvenile densities. This strategic investment in calling behaviour by females, based on juvenile cues that anticipate the future socio-sexual environment, likely reflects a response to avoid mating failure through competition with neighbouring signallers.

Population density can play a vital role in determining investment in reproductive behaviours and morphologies of invertebrates. Males reared in high-density environments, where competition is high but difficulties in locating mates are low, may invest more in reproductive structures associated with sperm competition such as testes, at the expense of those traits associated with mate location, such as antennae. In species where females advertise for mates, such as most moths, a high-density environment may also lead to a reduction in pheromonal signalling (calling) length and frequency as a result of high mate abundance. While such responses have been shown at the phenotypically plastic level in moths, heritable evolutionary adaptations have seldom been tested, and studies of how population density influences pheromone signalling strategies are scarce. Here we use behavioural assays and scanning electron microscopic measurements to test whether larval population density influences, at the genetic level, the ability of males to locate females and male investment into antennal morphology, in addition to its effect on the frequency and duration of female calling. We used two replicated populations of the Indian meal moth Plodia interpunctella that had experimentally evolved under high or low population densities for 35 generations. We found no significant divergence in antennal morphology or mate acquisition behaviours between the two density populations. These findings suggest that although population density has the ability to create plastic changes in both morphological and behavioural traits, this factor alone is unlikely to be causing evolutionary change in male and female signalling in this species.

Perinatal brain injury (PBI) to the developing white matter results in hypomyelination of axons and can cause long-term motor and cognitive deficits e.g. cerebral palsy. There are currently no approved therapies aimed at repairing the white matter following insult, underscoring the need to investigate the mechanisms underlying the pathogenesis of PBI. Microglia have been strongly implicated, but their function and heterogeneity in this context remain poorly understood, posing a barrier to the development of microglia-targeted therapies for white matter repair following PBI. In this review, we discuss the roles of microglia in normal white matter development and in PBI, and potential drug strategies to influence microglial responses in this setting.

An evaluation of the clinical yield of inpatient long-term video-EEG (vEEG) in a new epilepsy monitoring unit (EMU) was undertaken, with findings compared to the centre's prior method of bedside vEEG recording in a standard neurology ward, as reported in 2004. A retrospective analysis of neurophysiology reports for all adults who underwent elective vEEG monitoring in the EMU at Cork University Hospital between January 2015 and July 2016 was conducted. Of 115 vEEG studies in the EMU, 100 (87.0%) were deemed diagnostically conclusive, 14 (12.2%) failed to catch any clinical events and showed normal EEG throughout, and one (0.9%) captured spells of unclear clinical significance - the corresponding figures reported in 2004 for bedside vEEGs were 21.3%, 77% and 1.6%, respectively. The EMU offers a more effective method of recording inpatient vEEG, which aids decision-making and improves clinical outcomes. Some evidence-based measures which could further enhance diagnostic yield are discussed.

Glioblastoma (GBM) is the most common adult primary brain tumor, and the 5-year survival rate is less than 5%. GBM malignancy is driven in part by a population of GBM stem-like cells (GSCs) that exhibit indefinite self-renewal capacity, multipotent differentiation, expression of neural stem cell markers, and resistance to conventional treatments. GSCs are enriched in specialized niche microenvironments that regulate stem phenotypes and support GSC radioresistance. Therefore, identifying GSC-niche interactions that regulate stem phenotypes may present a unique target for disrupting the maintenance and persistence of this treatment resistant population. In this work, we engineered 3D scaffolds from temperature responsive poly(N-isopropylacrylamide-co-Jeffamine M-1000® acrylamide), or PNJ copolymers, as a platform for enriching stem-specific phenotypes in two molecularly distinct human patient-derived GSC cell lines. Notably, we observed that, compared to conventional neurosphere cultures, PNJ cultured GSCs maintained multipotency and exhibited enhanced self-renewal capacity. Concurrent increases in expression of proteins known to regulate self-renewal, invasion, and stem maintenance in GSCs (NESTIN, EGFR, CD44) suggest that PNJ scaffolds effectively enrich the GSC population. We further observed that PNJ cultured GSCs exhibited increased resistance to radiation treatment compared to GSCs cultured in standard neurosphere conditions. GSC radioresistance is supported in vivo by niche microenvironments, and this remains a significant barrier to effectively treating these highly tumorigenic cells. Taken in sum, these data indicate that the microenvironment created by synthetic PNJ scaffolds models niche enrichment of GSCs in patient-derived GBM cell lines, and presents tissue engineering opportunities for studying clinically important behaviors such as radioresistance in vitro.

Responses to angiotensin II (Ang II) were investigated in anaesthetised CD1 mice. Injections of Ang II caused dose-related increases in systemic arterial pressure that were antagonised by candesartan. Responses to Ang II were not altered by PD 123319. At the lowest dose studied (20 µg/kg i.v.), the inhibitory effects of candesartan were competitive, whereas at the highest dose (100 µg/kg i.v.), the dose-response curve for Ang II was shifted to the right in a non-parallel manner. The inhibitory effects of candesartan were selective and were similar in animals pretreated with enalaprilat to reduce endogenous Ang II production. Pressor responses to Ang II were not altered by propranolol, phentolamine or atropine, but were enhanced by hexamethonium. Increases in total peripheral resistance were inhibited by the AT1-receptor antagonist (ARB) but were not altered by AT2-receptor, alpha- or beta-receptor antagonists. These results suggest that pressor responses to Ang II are mediated by AT 1-receptors, are buffered by the baroreceptors, are not modulated by effects on AT2receptors, and that activation of the sympathetic nervous system plays little role in mediating rapid haemodynamic responses to the peptide in anaesthetised mice.

Traumatic mating (or copulatory wounding) is an extreme form of sexual conflict whereby male genitalia physically harm females during mating. In such species females are expected to evolve counter-adaptations to reduce male-induced harm. Importantly, female counter-adaptations may include both genital and non-genital traits. In this study, we examine evolutionary associations between harmful male genital morphology and female reproductive tract morphology and immune function across 13 populations of the seed beetle Callosobruchus maculatus . We detected positive correlated evolution between the injuriousness of male genitalia and putative female resistance adaptations across populations. Moreover, we found evidence for a negative relationship between female immunity and population productivity, which suggests that investment in female resistance may be costly due to the resource trade-offs that are predicted between immunity and reproduction. Finally, the degree of female tract scarring (harm to females) was greater in those populations with both longer aedeagal spines and a thinner female tract lining. Our results are thus consistent with a sexual arms race, which is only apparent when both male and female traits are taken into account. Importantly, our study provides rare evidence for sexually antagonistic coevolution of male and female traits at the within-species level.

Grit is a nuisance material that causes abrasive wear to mechanical equipment increasing maintenance and operational costs while reducing equipment performance and useful life. Grit that is not captured in the headworks accumulates in processes throughout the plant, reducing capacity and detention time, and adversely influencing flow and circulation patterns 2 . Deposited grit must be manually removed, handled, hauled and disposed. Abrasive wear, process inefficiencies and basin cleaning operations increase treatment plant operating expenses. Choosing a grit removal technology has often been based on equipment price with little regard for device efficacy and consequent grit removal efficiency. The industry has lacked an unbiased side-by-side comparison of the currently available technologies. As a result, owners and engineers are forced to navigate a field of, what can be conflicting, performance claims made by various equipment manufacturers. This situation is perpetuated by the fact that there is no accepted, peer reviewed test standard for grit sampling and analysis. The purpose of this paper is to encapsulate various grit removal system performance data generated by a consistent and repeatable sampling and analysis methodology for the purpose of comparing virtually all grit removal technologies in terms of their effectiveness. Results determined with this sampling method corroborates with the operating history and performance at the tested plants with respect to grit removal, suggesting the accuracy of the test method 6. The data provides an unbiased side-by-side comparison of the actual performance of grit technologies based on a repeatable sampling and analysis methodology that owners and engineers can utilize to protect plants from deposition, abrasive wear and associated costs from this nuisance material.

Phenotypic plasticity allows animals to maximize fitness by conditionally expressing the phenotype best adapted to their environment. Although evidence for such adjustment in reproductive tactics is common, little is known about how phenotypic plasticity evolves in response to sexual selection. We examined the effect of sexual selection intensity on phenotypic plasticity in mating behavior using the beetle Callosobruchus maculatus. Male genital spines harm females during mating and females exhibit copulatory kicking, an apparent resistance trait aimed to dislodge mating males. After exposing individuals from male- and female-biased experimental evolution lines to male- and female-biased sociosexual environments, we examined behavioral plasticity in matings with standard partners. While females from female-biased lines kicked sooner after exposure to male-biased sociosexual contexts, in male-biased lines this plasticity was lost. Ejaculate size did not diverge in response to selection history, but males from both treatments exhibited plasticity consistent with sperm competition intensity models, reducing size as the number of competitors increased. Analysis of immunocompetence revealed reduced immunity in both sexes in male-biased lines, pointing to increased reproductive costs under high sexual selection. These results highlight how male and female reproductive strategies are shaped by interactions between phenotypically plastic and genetic mechanisms of sexual trait expression.

Trans-generational immune priming is the transmission of enhanced immunity to offspring following a parental immune challenge. Although within-generation increased investment into immunity demonstrates clear costs on reproductive investment in a number of taxa, the potential for immune priming to impact on offspring reproductive investment has not been thoroughly investigated. We explored the reproductive costs of immune priming in a field cricket, Teleogryllus oceanicus. To assess the relative importance of maternal and paternal immune status, mothers and fathers were immune-challenged with live bacteria or a control solution and assigned to one of four treatments in which one parent, neither or both parents were immune-challenged. Families of offspring were reared to adulthood under a food-restricted diet, and approximately 10 offspring in each family were assayed for two measures of immunocompetence. We additionally quantified offspring reproductive investment using sperm viability for males and ovary mass for females. We demonstrate that parental immune challenge has significant consequences for the immunocompetence and, in turn, reproductive investment of their male offspring. A complex interaction between maternal and paternal immune status increased the antibacterial immune response of male offspring. This increased immune response was associated with a reduction in son's sperm viability, implicating a trans-generational resource trade-off between investment into immunocompetence and reproduction. Our data also show that these costs are sexually dimorphic, as daughters did not demonstrate a similar increase in immunity, despite showing a reduction in ovary mass.

The sexy-sperm hypothesis proposes that polyandrous females will have a selective advantage over monandrous females as their sons will be sired by males with competitively superior sperm and will inherit this trait. Although the good-sperm hypothesis also predicts that offspring will be sired by males with competitively superior sperm, it additionally assumes a positive correlation between offspring sperm quality and the general viability of both sons and daughters. We examined the potential for sexy-sperm and good-sperm processes by exploring the effect of polyandry on offspring sperm quality and immunocompetence in the field cricket, Teleogryllus oceanicus, a species in which sperm viability predicts sperm competitive ability. In the parental generation, females were mated monandrously or polyandrously, where each female received 3 matings. We reared the resultant offspring through to maturity and assayed approximately 10 offspring per family for both sperm viability and immunity. We found that male offspring from polyandrous mothers had higher sperm viability, but that this was not phenotypically associated with male or female offspring condition, as measured by either immune function or ability to survive a bacterial infection. Thus, our data are consistent with a sexy-sperm, but not a good-sperm model in explaining the evolution of polyandry in this species.

Foot drop is a complex symptom with a considerable range in aetiology, severity and prognosis. We aim to characterise the aetiologies of foot drop and assess the diagnostic contribution of neurophysiologic testing (NCS/EMG). Retrospective review of consecutive referrals of foot drop to the Neurophysiology Department in Cork University Hospital was performed over a two year period (January 2012 to December 2013). Of a total of 59 referrals, common peroneal nerve (CPN) palsy comprised only slightly more than half of cases; 3(5%) have central origin; 3(5%) have motor neuron disease. Six (10%) have diabetes; 7(12%) have cancer; 5(8%) were bilateral. NCS/EMG altered initial working diagnosis in 14 out of 52 (27%) cases whereby initial diagnosis was provided. However one-third of all cases revealed additional coexistent pathology in an anatomic location remote to that of the primary diagnosis. Foot drop with central and proximal localisations are important and under recognised. NCS/EMG is valuable and also reveals additional pathology which warrants investigation.