Resurgence of seasonal influenza driven by A/H3N2 and B/Victoria in succession during the 2023-2024 season in Beijing showing increased population susceptibility.

During the COVID-19 pandemic, non-pharmaceutical interventions were introduced to reduce exposure to respiratory viruses. However, these measures may have led to an "immunity debt" that could make the population more vulnerable. The goal of this study was to examine the transmission dynamics of seasonal influenza in the years 2023-2024. Respiratory samples from patients with influenza-like illness were collected and tested for influenza A and B viruses. The electronic medical records of index cases from October 2023 to March 2024 were analyzed to determine their clinical and epidemiological characteristics. A total of 48984 positive cases were detected, with a pooled prevalence of 46.9% (95% CI 46.3-47.5). This season saw bimodal peaks of influenza activity, with influenza A peaked in week 48, 2023, and influenza B peaked in week 1, 2024. The pooled positive rates were 28.6% (95% CI 55.4-59.6) and 18.3% (95% CI 18.0-18.7) for influenza A and B viruses, respectively. The median values of instantaneous reproduction number were 5.5 (IQR 3.0-6.7) and 4.6 (IQR 2.4-5.5), respectively. The hospitalization rate for influenza A virus (2.2%, 95% CI 2.0-2.5) was significantly higher than that of influenza B virus (1.1%, 95% CI 0.9-1.4). Among the 17 clinical symptoms studied, odds ratios of 15 symptoms were below 1 when comparing influenza A and B positive inpatients, with headache, weakness, and myalgia showing significant differences. This study provides an overview of influenza dynamics and clinical symptoms, highlighting the importance for individuals to receive an annual influenza vaccine.

Healthy together Victoria and childhood obesity study: effects of a large scale, community-based cluster randomised trial of a systems thinking approach for the prevention of childhood obesity among secondary school students 2014-2016.

BACKGROUND: Healthy Together Victoria (HTV) was a Victorian Government initiative that sought to reduce the prevalence of overweight and obesity through targeting chronic disease risk factors including physical activity, poor diet quality, smoking, and harmful alcohol use. The intervention involved a boosted workforce of > 170 local-level staff in 12 communities; employed to deliver system activation around health and wellbeing for individuals, families and communities. A cluster randomised trial (CRT) of a systems thinking approach to obesity prevention was embedded within HTV. We present the two-year changes in overweight and obesity and associated behaviours among secondary school students across Victoria, Australia. METHODS: Twenty-three geographically bounded areas were randomised to intervention (12 communities) or comparison (11 communities). Randomly selected secondary schools within each community were invited to participate in the trial in 2014 and 2016. Students in Grade 8 (aged approximately 13-15 years) and Grade 10 (aged approximately 15-16 years) at participating schools were recruited using an opt-out approach across July-September 2014 and 2016. Primary outcomes were body mass index (BMI) and waist circumference. Secondary outcomes were physical activity, sedentary behaviour, diet quality, health-related quality of life, and depressive symptoms. Linear mixed models were fit to estimate the intervention effect adjusting for child/school characteristics. RESULTS: There were 4242 intervention children and 2999 control children in the final analysis. For boys, the two-year change showed improvement in intervention versus control for waist circumference (difference in change: - 2.5 cm; 95% confidence interval [CI]: - 4.6, - 0.5) and consumption of sugar-sweetened beverages per day (< 1 serve: 8.5 percentage points; 95% CI: 0.6, 16.5). For girls, there were no statistically significant differences between conditions. CONCLUSIONS: HTV seemed to produce favourable changes in waist circumference and sugar-sweetened beverage consumption for boys, however, no effect on BMI was observed. Although the HTV intervention was cut short, and the period between data collection points was relatively short, the changes observed in HTV contribute to the growing evidence of whole-of-community interventions targeting childhood obesity. TRIAL REGISTRATION: This trial is unregistered. The intervention itself was a policy setting delivered by government and our role was the collection of data to evaluate the effect of this natural experiment. That is, this study was not a trial from the classical point of view and we were not responsible for the intervention.

Cost-utility analysis of add-on vericiguat for the treatment of chronic heart failure with reduced ejection fraction in China.

OBJECTIVE: This study aimed to evaluate the cost-utility of the addition of vericiguat for treating chronic heart failure (CHF) in China from the healthcare payer's perspective. METHODS: A Markov model was built to estimate the cost and utility of treating CHF using vericiguat plus standard treatment (vericiguat group) vs. standard treatment alone (standard treatment group). The clinical parameters (mortality of cardiovascular and hospitalization rate of HF) were calculated according to the VICTORIA clinical trial. The HF cost and utility data were obtained from the literature published in China. One-way sensitivity analysis and probability sensitivity analysis were performed. RESULTS: According to the 13-year model, vericiguat was more expensive (155599.07 CNY vs. 259396.83 CNY) and more effective (4.41 QALYs vs. 4.54 QALYs). The incremental cost-utility ratio (ICUR) was 802389.27 CNY per QALY. One-way sensitivity analysis revealed that cardiovascular mortality in the two groups was the parameter that had the greatest impact on the results. The GDP per capita in 2022 in China was 85,700 CNY. The probability sensitivity analysis (PSA) showed that the probability of vericiguat being cost-effective was only 41.7% at the willingness-to-pay (WTP) threshold of 3 times GDP per capita (257,100 CNY). CONCLUSIONS: In China, the treatment of CHF with vericiguat is not cost-effective. The drug price could decrease to 145.8 CNY, which could be considered cost-effective.

Temporal changes in temperature-related mortality in relation to the establishment of the heat-health alert system in Victoria, Australia.

Extreme heat alerts are the most common form of weather forecasting services used in Australia, yet very limited studies have documented their effectiveness in improving health outcomes. This study aimed to examine the temporal changes in temperature-related mortality in relation to the activation of the heat-health alert and response system (HARS) in the State of Victoria, Australia. We examined the relationship between temperatures and mortality using quasi-Poisson regression and the distributed lag non-linear model (dlnm) and compared the temperature-mortality association between the two periods: period 1- prior-HARS (1992-2009) and period 2- post-HARS (2010-2019). Since the HARS heavily weights heatwave effects, we also compared the main effects of heatwave events between the two periods. The heatwaves were defined for three levels, including 3 consecutive days at 97th, 98th, and 99th percentiles. We also controlled the potential confounding effect of seasonality by including a natural cubic B-spline of the day of the year with equally spaced knots and 8 degrees of freedom per year. The exposure-response curve reveals the temperature mortality was reduced in period 2 in comparison with period 1. The relative risk ratios (RRR) of Period 2 over Period 1 were all less than one and gradually decreased from 0.86 (95% CI, 0.72-1.03) to 0.64 (95% CI, 0.33-1.22), and the differences in attributable risk percent increased from 13.2 to 25.3%. The reduction in the risk of heatwave-related deaths decreased by 3.4% (RRp1 1.068, 95% CI, 1.024-1.112 versus RRp2 1.034, 95% CI, 0.986-1.082) and 10% (RRp1 1.16, 95% CI, 1.10-1.22 versus RRp2 1.06, 95% CI, 1.002-1.119) for all groups of people. The study indicated a decrease in heat-related mortality following the operation of HARS in Victoria under extreme heat and high-intensity heatwaves conditions. Further studies could investigate the extent of changes in mortality among populations of differing socio-economic groups during the operation of the heat-health alert system.

Legacy effects of historical gold mining on floodplains of an Australian river.

The gold rush at the end of the nineteenth century in south-eastern Australia resulted in the mobilization and re-deposition of vast quantities of tailings that modified the geomorphology of the associated river valleys. Previous studies of contamination risk in these systems have either been performed directly on mine wastes (e.g., battery sand) or at locations close to historical mine sites but have largely ignored the extensive area of riverine alluvial deposits extending downstream from gold mining locations. Here we studied the distribution of contaminant metal(loids) in the Loddon River catchment, one of the most intensively mined areas of the historical gold-rush period in Australia (1851-1914). Floodplain alluvium along the Loddon River was sampled to capture differences in metal and metalloid concentrations between the anthropogenic floodplain deposits and the underlying original floodplain. Elevated levels of arsenic up to 300 mg-As/kg were identified within the anthropogenic alluvial sediment, well above sediment guidelines (ISQG-high trigger value of 70 ppm) and substantially higher than in the pre-mining alluvium. Maximum arsenic concentrations were found at depth within the anthropogenic alluvium (plume-like), close to the contact with the original floodplain. The results obtained here indicate that arsenic may pose a significantly higher risk within this river catchment than previously assessed through analysis of surface floodplain soils. The risks of this submerged arsenic plume will require further investigation of its chemical form (speciation) to determine its mobility and potential bioavailability. Our work shows the long-lasting impact of historical gold mining on riverine landscapes.

Adult Mental Health Presentations to Emergency Departments in Victoria, Australia between January 2018 and October 2020: Changes Associated with COVID-19 Pandemic Public Health Restrictions.

The COVID-19 pandemic and associated public health measures altered patterns of help-seeking for mental health, with increases in emergency department utilisation reported. We examined the association between COVID-19 restrictions and adult emergency department (ED) mental health presentations in Victoria, Australia, through secondary analysis of data from 39 public EDs across the state. Participants were all patients (18+ years) presenting between 1 January 2018 and 31 October 2020 with mental health or intentional self-harm. The main outcome was number of presentations for each mental health condition, by patient age, socioeconomic status (SES), location, and ED triage category. We used a Poisson regression model to compare predicted monthly ED presentations based on trends from 2018, 2019 and 2020 (up to 31 March), with observed presentations during the initial months of the COVID-19 pandemic (1 April to 31 October 2020). There was an average of 4,967 adult mental health presentations per month pre-COVID-19 (1 January-31 March 2020) and 5,054 per month during the COVID-19 period (1 April-31 October 2020). Compared to predicted incidence, eating disorder presentations increased 24.0% in the COVID-19 period, primarily among higher SES females aged 18-24 years. Developmental/behavioural disorder presentations decreased by 19.7% for all age groups. Pandemic restrictions were associated with overall increases in monthly adult ED presentations for mental health, with some disorders increasing and others decreasing. Accessibility of acute mental health services needs to be addressed to meet changing demand and ensure services are responsive to changes in presentations resulting from future public health challenges.

Conventional HE staining combined with two special staining methods to identify antemortem stab wound in case with highly decomposed mutilated corpses.

This study aims to identify an antemortem neck stab wound on a highly decomposed, headless and mutilated body by conventional hematoxylin-eosin (HE) staining combined with Ponceau-Victoria blue B staining (P-VB staining) and Masson staining. Specifically, a tissue sample was excised from the skin and muscle tissue at the junction of the normal and brownish discolored areas around the suspected stabbing tract of the left neck, in the upper and lower wound-clavicle-shoulder region. Conventional HE staining only provides a morphological and structural outline of the tissue, with both the injury hemorrhage and local connective tissue appearing eosinophilic pink. However, P-VB staining shows obvious contrast between the injury hemorrhage and connective tissue, with the former appearing yellow-green and the latter appearing orange-red. Similarly, Masson staining of the injury hemorrhage and connective tissue contrast clearly with purple-red and dark blue, respectively. Therefore, our study highlights that conventional HE staining with the combination of P-VB staining and Masson staining allowed for a clearer and corroborated identification of antemortem injury and hemorrhage from the stab wound in highly decomposed mutilated corpses.

Use of point-of-care ultrasound during cardiac arrest in the intensive care unit: A cross-sectional survey.

BACKGROUND: There is growing interest in the use of point-of-care ultrasound during cardiac arrest, but few studies document its use in the intensive care unit. OBJECTIVE: We hypothesised this may reflect a low prevalence of use of point-of-care ultrasound during cardiac arrest or negative attitudes towards its use. We aimed to determine the self-reported prevalence, attitudes towards, and barriers to use of point-of-care ultrasound during cardiac arrest in the intensive care unit. METHODS: We conducted a web-based survey over 3 months (08/08/2022-06/11/2022), of intensive care unit consultants and registrars in Victoria, Australia. Descriptive and mixed-methods analyses of Likert-type and free-text answers were performed. RESULTS: The response rate was 91/398 (22.8%), split evenly between consultants and registrars. There was a broad range of clinical and ultrasound experience. Only 22.4% (22/91) of respondents reported using point-of-care ultrasound 75-100% of the time during their management of cardiac arrest. Respondents rated the value they place in point-of-care ultrasound during cardiac arrest 3 (interquartile range: 3-4) and that of a "skilled operator" 4 ((interquartile range; 4-5) on a 5-point scale. Free-text analysis suggested exclusion of "tamponade" (40/80 [50%] comments) as the most valuable use-case and "skill" as a personal barrier (20/73 [27.4%] comments). Personal and departmental barriers were not rated highly, although registrars perceived "lack of a structured training program" as a barrier. Respondents were equivocal in the value they gave point-of-care ultrasound during cardiac arrest but saw greater value when conducted by a skilled operator. CONCLUSIONS: Point-of-care ultrasound was reported to be infrequently used in cardiac arrest, mostly due to self-perceived skill and lack of a structured training program.

Cocirculation of A(H3N2) and B/Victoria increased morbidity in hospitalized patients in the 2019-2020 A(H1N1)pdm09 predominant influenza season in Israel.

Community surveillance found the 2019-2020 A(H1N1)pdm09 predominant influenza season in Israel to be a high-intensity season with an early and steep morbidity peak. To further characterize disease severity in the 2019-2020 season, we analyzed a cohort of hospitalized patients with laboratory-confirmed influenza from this season (n = 636). Quantitative polymerase chain reaction was performed on clinical samples to detect the presence of influenza. Demographic, clinical, and laboratory data were retrieved via electronic health records and MDClone. Electronic health records were accessed to obtain data on intensive care unit patients, missing data and for data verification purposes. Univariate analysis was performed to compare demographic, comorbidity, and clinical characteristics across the three influenza strains. The A(H1N1)pdm09 predominant 2019-2020 influenza season in Israel was characterized by an early and steep morbidity peak, vaccine delays and shortages, and with the A(H3N2) and B/Victoria strains disproportionately targeting children and young adults, most probably due to reduced immunity to these strains. A greater proportion of children <5 years infected with A(H3N2) and B/Victoria developed severe influenza compared with those infected with A(H1N1)pdm09. Our study emphasizes the vulnerability of infants and young children in the face of rapidly evolving influenza strains and underscores the importance of influenza prevention measures in this population.

Factors Associated with Short and Long Term Mobility and HIV Risk of Women Living in Fishing Communities Around Lake Victoria in Kenya, Tanzania, and Uganda: A Cross Sectional Survey.

Mobility is linked to negative HIV care continuum outcomes. We sought to understand factors associated with short and long term mobility among women in fishing communities in Kenya, Tanzania, and Uganda. From 2018 through 2019 we conducted a cross-sectional survey of women aged 15 years and above, randomly selected from a census of six fishing villages, around Lake Victoria. Data collected included: demographics, risky sexual behaviour on the most recent trip, and travel behaviour in the previous 4 months. Mobility was recorded as any overnight trip outside the participant's village. A two-level multinomial logistic regression model was used to determine the associated factors. A total of 901 participants were enrolled, of whom 645 (71.6%) reported travelling (53.4%; short and 18.2% long term trips). Five factors were associated with long term travel: age, travel purpose, frequency of travel, sexual behaviour while travelling, and destination. Trips made by women aged 46-75 years were less likely to be long term. Long term trips were more common if the trip was to visit, rather than to trade, and more common for women who reported one or two trips rather than three or more trips. Women who made long term trips were more likely to engage in unprotected sex while on a trip. Women who travelled to a regional town/district or another town/district were more likely to take long term trips. The factors associated with travel duration among women living in fishing communities could inform planning of future health care interventions in these communities.

Japan should initiate the discussion on voluntary assisted dying legislation now.

BACKGROUND: No laws or official guidelines govern voluntary assisted dying (VAD) in Japan. A legislative bill on the termination of life-sustaining measures has yet to be sent to deliberations for legislation, due to strong opposition that has prevented it from being submitted to the Diet. However, Japan has recently witnessed several cases involving VAD. MAIN TEXT: Against this backdrop, we argue that Japan should begin discussion on VAD legislation, referring to the Voluntary Assisted Dying Act 2017 (VADA2017), which was established in 2017 in Victoria, Australia. VADA2017 puts in place a wide range of stringent safeguards and is considered worldwide to be the safest and most conservative policy on a physician offering assisted dying based on the patient's premeditated request. We consider what opposing opinions from society would arise in response to the VADA2017. Among these will include arguments against VAD itself, those against the validation of this act, and opinions that oppose even the initiation of the dialogue on VAD. CONCLUSIONS: We conclude that to protect the right to life among those placed in vulnerable positions and, at the same time, to respect decision-making of those who wish for immediate death due to unbearable suffering, the dialogue must immediately begin with that on introducing a policy more conservative than that of the VADA2017, which solidly considers arguments against VAD.

Food system policy making and innovation at the local level: Exploring the response of Australian local governments to critical food systems issues.

ISSUES ADDRESSED: Urgent action is required by all levels of government to create a food system capable of nourishing a rapidly growing population while remaining within planetary boundaries. This study investigated policies and programs implemented by Australian local governments (LGs) that aim to contribute to a healthy, sustainable and equitable food system. METHODS: An online survey was completed by LGs (n = 64) in New South Wales and Victoria, Australia. Questions focused on LGs' food system-related policies and programs, barriers to and enablers of engaging in food system work and organisational responsibilities for food system work. RESULTS: Preventing food waste, organising food-related social/cultural events and providing potable water were the most commonly reported activities. Few LGs reported policies/activities on market gardening or sustainable agricultural practices, or strengthening food system resilience. LGs implemented a wide range of initiatives, such as hosting food forums, using research to identify and address food access issues and providing healthy food and drink options within LG-owned/managed facilities. Enablers of food system work included internal LG support, human resources, external funding and partnerships. Barriers included lack of community interest, short-term and/or project-based funding, internal governance issues and restrictive state government planning frameworks. CONCLUSION: Australian LGs undertake a wide range of actions addressing diverse food system issues; however, internal and external barriers constrain their involvement in creating a healthy, sustainable and equitable food system. SO WHAT?: Legislative reform, combined with increased financial and human resource capacity, would support LGs to expand, strengthen and sustain their food system work.

Barriers to linkage and retention in HIV care still persist among adolescent girls and young women in western Kenya.

Adolescent girls and young women (AGYW) in sub-Saharan Africa experience delayed linkage to and poor retention in HIV care. Identifying and addressing specific barriers in HIV care programming is important to achieving the upgraded UNAIDS 95-95-95 targets and epidemic control. We examined these challenges among 103 HIV-positive AGYW in and out of HIV care in communities around Lake Victoria in western Kenya as part of a larger qualitative study to identify drivers of HIV testing and HIV care utilisation in key populations. We used the social-ecological model to guide development of interview guides. Individual-level barriers included denial and forgetfulness and gendered household responsibilities, medication side effects, especially if taken without food, pills being too big and difficult to swallow and the burden of a daily medication-taking regimen. Interpersonal barriers included troubled family relationships and pervasive fears of stigma and discrimination by friends and family. Communitylevel barriers were stigmatising attitudes toward people living with HIV. Health-system barriers included negative provider attitudes and confidentiality breaches. At the structural level, participants noted high costs due to long travel times to facilities, long clinic waiting times, household food insecurity and school and work commitments. AGYW's limited decision-making autonomy due to age and gender norms, including their reliance on the authority of older adults, makes these barriers especially troubling. Innovative treatment approaches that take into account the unique vulnerabilities of AGYW are urgently needed.

Comparing Voluntary Assisted Dying Laws in Victoria and Western Australia: Western Australian Stakeholders' Perspectives.

In 2021, two years after voluntary assisted dying (VAD) laws commenced in Victoria, Western Australia (WA) was the second Australian jurisdiction to permit VAD. While the two regimes are broadly similar, key differences exist. This article reports on findings from a qualitative study of WA participants with VAD experience across four stakeholder groups (patients and families; health practitioners; regulators and VAD system personnel; and health and professional organisation representatives), focusing particularly on participants' reflections on aspects of the WA VAD regime which differs from that in Victoria and the practical implications of those differences. Globally, participants viewed VAD as operating smoothly in Western Australia and, despite identifying some areas for improvement, that WA's model was more functional and accessible than Victoria's. By comparing two different VAD models, this article's findings add to growing empirical evidence about VAD in Australia and can inform future VAD reforms and reviews.

Application of P/VB staining to identify antemortem injury in a decomposed cadaver.

It is challenging in forensic pathology to determine whether an injury is formed antemortem or postmortem in putrefied tissues. Hematoxylin-eosin (HE) staining fails to work in highly decomposed corpses. Ponceau/Victoria blue B (P/VB) staining is usually used to show collagen fibers and muscles. Here, we used P/VB to show antemortem laceration injury on the scalp in a severely decomposed cadaver 1.5 years after death. This method is a simple and alternative method for the diagnosis of antemortem injury.

Outcomes of rural generalist internship training in Victoria, Australia.

INTRODUCTION: Victoria, Australia commenced its first Rural Community Internship Training program in 2012 to support the development of rural generalist (RG) doctors. These general practitioners have additional skills to work at a broad scope to deliver the range of primary care and additional specialist services that communities need. Unlike most internships, which are wholly hospital-based and delivered mostly within larger metropolitan and regional centres, this RG internship training model involves completing general practice experience in smaller rural communities working with RGs and visiting specialists. This study aimed to explore the characteristics and satisfaction of doctors who participate in RG internship training in Victoria and their workforce outcomes. METHODS: Between October and November 2021, a retrospective 10-minute anonymous survey invitation was sent to all contactable interns (n=222) who had completed/were completing the RG internship training (2012-2021). The survey was co-designed with RG internship managers and other stakeholders of a statewide evaluation advisory group, informed by the latest evidence regarding RG medicine and rural training predictors, and outcomes of interest. Participants completed the survey using Microsoft Forms, with three invitations circulated to an up-to-date email address maintained by the internship program. Collected data were analysed descriptively, by subgroup, to explore training pathway outcomes by region, training stage and specialty choice. Workforce distribution outcomes were defined in line with objectives of the program and predetermined indicators of RG scope. Results were compared with the benchmarks of rural workforce training outcomes in Australia using recent research. RESULTS: There were 59 participants (27% response rate); 81% were in postgraduate years 3-7. Respondents included 54% male, 17% rurally bonded, 39% of rural origin, 34% having had more than 3 months rural undergraduate training and 48% doing RG training where they previously did undergraduate training. All were satisfied/very satisfied with the RG training and 61% were working in general practice (excluding the prevocational group). Overall, 40% were currently working in the same rural region as their internship (including three who were currently interns), 56% continued to complete some prevocational training in the same region as their RG internship, while 20% had gone on to be currently based in smaller rural communities (Modified Monash Model locations 4-7) and 44% to be working part-time in smaller rural communities. Overall, 42% self-identified as working as an RG and nearly all (97%) met at least one of the key indicators of extended (RG) scope. In all areas the RG internship outcomes were better than the national benchmarks from published evidence about rural training. CONCLUSION: This study provides evidence from doctors up to 9 years after completing their RG internship. Compared with industry benchmarks, the RG internships attract rurally intentioned and rurally experienced doctors who may be likely to remain in the same rural region as their undergraduate rural medical training and continue their postgraduate training in the same region. They were all satisfied with RG internship training, had high propensity to follow a general practice career and work at broad scope in smaller communities. Importantly, they intended to stay in the region where they trained. This suggests RG internship programs are a positive intervention for promoting an RG workforce.

Explosive networking: The role of adaptive host radiations and ecological opportunity in a species-rich host-parasite assembly.

Many species-rich ecological communities emerge from adaptive radiation events. Yet the effects of adaptive radiation on community assembly remain poorly understood. Here, we explore the well-documented radiations of African cichlid fishes and their interactions with the flatworm gill parasites Cichlidogyrus spp., including 10,529 reported infections and 477 different host-parasite combinations collected through a survey of peer-reviewed literature. We assess how evolutionary, ecological, and morphological parameters determine host-parasite meta-communities affected by adaptive radiation events through network metrics, host repertoire measures, and network link prediction. The hosts' evolutionary history mostly determined host repertoires of the parasites. Ecological and evolutionary parameters predicted host-parasite interactions. Generally, ecological opportunity and fitting have shaped cichlid-Cichlidogyrus meta-communities suggesting an invasive potential for hosts used in aquaculture. Meta-communities affected by adaptive radiations are increasingly specialised with higher environmental stability. These trends should be verified across other systems to infer generalities in the evolution of species-rich host-parasite networks.

Molecular Detection of Haplorchis pumilio Eggs in Schoolchildren, Kome Island, Lake Victoria, Tanzania.

A survey of intestinal helminths targeting 1,440 schoolchildren in 12 primary schools on Kome Island (Lake Victoria), Tanzania, revealed small trematode eggs in 19 children (1.3%), seemingly of a species of Haplorchis or Heterophyes. The eggs were molecularly confirmed to be Haplorchis pumilio on the basis of 18S and 28S rDNA sequences.

Genomic Signatures for Species-Specific Adaptation in Lake Victoria Cichlids Derived from Large-Scale Standing Genetic Variation.

The cichlids of Lake Victoria are a textbook example of adaptive radiation, as >500 endemic species arose in just 14,600 years. The degree of genetic differentiation among species is very low due to the short period of time after the radiation, which allows us to ascertain highly differentiated genes that are strong candidates for driving speciation and adaptation. Previous studies have revealed the critical contribution of vision to speciation by showing the existence of highly differentiated alleles in the visual opsin gene among species with different habitat depths. In contrast, the processes of species-specific adaptation to different ecological backgrounds remain to be investigated. Here, we used genome-wide comparative analyses of three species of Lake Victoria cichlids that inhabit different environments-Haplochromis chilotes, H. sauvagei, and Lithochromis rufus-to elucidate the processes of adaptation by estimating population history and by searching for candidate genes that contribute to adaptation. The patterns of changes in population size were quite distinct among the species according to their habitats. We identified many novel adaptive candidate genes, some of which had surprisingly long divergent haplotypes between species, thus showing the footprint of selective sweep events. Molecular phylogenetic analyses revealed that a large fraction of the allelic diversity among Lake Victoria cichlids was derived from standing genetic variation that originated before the adaptive radiation. Our analyses uncovered the processes of species-specific adaptation of Lake Victoria cichlids and the complexity of the genomic substrate that facilitated this adaptation.

Genetic architecture of adaptive radiation across two trophic levels.

Evolution of trophic diversity is a hallmark of adaptive radiation. Yet, transitions between carnivory and herbivory are rare in young adaptive radiations. Haplochromine cichlid fish of the African Great Lakes are exceptional in this regard. Lake Victoria was colonized by an insectivorous generalist and in less than 20 000 years, several clades of specialized herbivores evolved. Carnivorous versus herbivorous lifestyles in cichlids require many different adaptations in functional morphology, physiology and behaviour. Ecological transitions in either direction thus require many traits to change in a concerted fashion, which could be facilitated if genomic regions underlying these traits were physically linked or pleiotropic. However, linkage/pleiotropy could also constrain evolvability. To investigate components of the genetic architecture of a suite of traits that distinguish invertivores from algae scrapers, we performed quantitative trait locus (QTL) mapping using a second-generation hybrid cross. While we found indications of linkage/pleiotropy within trait complexes, QTLs for distinct traits were distributed across several unlinked genomic regions. Thus, a mixture of independently segregating variation and some pleiotropy may underpin the rapid trophic transitions. We argue that the emergence and maintenance of associations between the different genomic regions underpinning co-adapted traits that evolved and persist against some gene flow required reproductive isolation.