Pair housing of laboratory macaques is widely considered to lead to positive changes in well-being, yet the process of introduction is viewed as potentially stressful and risk-prone. Behavioral and physiological data were collected on eight adult male rhesus macaques before, during, and after the process of introduction, in order to measure the initial stress of introduction as well as long-term changes in well-being. Socially experienced subjects, all implanted with biotelemetry devices, were studied in five successive phases: baseline (singly housed), 1 day each of protected contact and full contact introduction, post-introduction (1–3 weeks after introduction), and settled pairs (≥20 weeks after introduction). One hundred and seventy-six hours of behavioral data and 672 hr of heart rate data were analyzed. Fecal cortisol was also measured for the baseline, post-introduction, and settled pair phases. All introductions were successful and subjects showed no physiological or behavioral signs of stress, such as increased heart rate, abnormal behavior, or psychological indices of distress (depressive/anxiety-related behavior). Agonism was minimal throughout the introduction process and over the subsequent months; only one wound was incurred over the course of the study. Levels of abnormal behaviors, psychological indices of distress, locomotion, inactivity, and affiliation showed improvements within several weeks after introduction; these changes were still present 5–9 months later for the latter two categories. Heart rates during introduction fell significantly in the settled pair phase, and also varied predictably with time of day. Fecal cortisol levels were lower in settled pairs than in single housing. The fact that reductions in abnormal behavior did not persist over the long term may have been confounded by increasing duration of time spent caged. The results of this study may be of practical use for designing and monitoring social introductions and suggest that managers should not dismiss the feasibility of successful pairing of adult male rhesus macaques.
Rhesus macaques; social introductions; biotelemetry; stress
The early introduction of solid foods before 4 months of age has been associated with an increased risk of diarrhoea in infancy and a greater risk of wheeze and increased percentage body fat and weight in childhood. The purpose of this study was to identify the level of compliance with national recommendations related to the timing of the introduction of solid foods and to describe the maternal and infant characteristics associated with the timing of the introduction of solids.
Subjects were 519 participants in the second longitudinal Perth Infant Feeding Study (PIFS II) recruited from two maternity hospitals in Perth, Western Australia in 2002/3. Data collected prior to, or shortly after discharge from hospital, and at 4, 10, 16, 22, 32, 40 and 52 weeks postpartum included timing of the introduction of solid foods and a variety of maternal and infant characteristics associated with the introduction of solid foods. Multivariate logistic regression was used to identify those factors associated with the risk of introducing solid foods early, which for the purposes of this study was defined as being before 17 weeks.
The median age of introduction of solid foods was 17.6 weeks. In total, 44% of infants had received solids before 17 weeks and 93% of infants had received their first solids before 26 weeks of age. The strongest independent predictors of the early introduction of solids were young maternal age, mother smoking prior to pregnancy and not fully breastfeeding at 4 weeks postpartum. In general, mothers introduced solids earlier than recommended because they perceived their baby to either need them or be ready for them.
This study showed a high level of non-compliance among Australian mothers with the infant feeding recommendation related to the timing of solids that was current at the time. In order to improve compliance health professionals need to be aware of those groups least likely to comply with recommendations and their reasons for non-compliance. Infant feeding recommendations need to be evidence-based, uniformly supported by professionals and widely, clearly and consistently articulated if higher rates of compliance are to be achieved in the future.
Theory suggests that introduction effort (propagule size or number) should be a key determinant of establishment success for exotic species. Unfortunately, however, propagule pressure is not recorded for most introductions. Studies must therefore either use proxies whose efficacy must be largely assumed, or ignore effort altogether. The results of such studies will be flawed if effort is not distributed at random with respect to other characteristics that are predicted to influence success. We use global data for more than 600 introduction events for birds to show that introduction effort is both the strongest correlate of introduction success, and correlated with a large number of variables previously thought to influence success. Apart from effort, only habitat generalism relates to establishment success in birds.
Average inoculum size and number of introductions are known to have positive effects on population persistence. However, whether these factors affect persistence independently or interact is unknown. We conducted a two-factor experiment in which 112 populations of parthenogenetic Daphnia magna were maintained for 41 days to study effects of inoculum size and introduction frequency on: (i) population growth, (ii) population persistence and (iii) time-to-extinction. We found that the interaction of inoculum size and introduction frequency—the immigration rate—affected all three dependent variables, while population growth was additionally affected by introduction frequency. We conclude that for this system the most important aspect of propagule pressure is immigration rate, with relatively minor additional effects of introduction frequency and negligible effects of inoculum size.
colonization; Daphnia magna; immigration; propagule pressure; renewal process
Reporting templates are increasingly common in all fields of pathology. In this paper, we present an assessment of the impact of a thyroid fine needle aspiration cytology (FNAC) template on diagnostic classification and cytohistologic concordance.
Materials and Methods:
A thyroid FNAC reporting template was developed and introduced at a university teaching hospital. We examined FNAC reports for a five-month period before introduction of the template and compared these to the five month period after the template introduction. We recorded diagnostic categorization as well as cytohistologic correlation.
A total of 168 cases were identified in the five month period prior to the introduction of the reporting template and 172 cases in the five month period after the introduction of the reporting template. The template appeared to improve the diagnostic precision of benign conditions without altering the proportion of cases classified as unsatisfactory, benign or abnormal. There was no significant difference in the rate of cytohistologic concordance before and after the template introduction.
The introduction of a reporting template for thyroid FNAC improved diagnostic precision of benign conditions and did not alter the general diagnostic classification or cytohistologic concordance.
Diagnosis; fine needle aspiration cytology (FNAC); thyroid; reporting template
Voluntary wheel running (WR) is a form of physical activity in rodents that influences ingestive behavior. The present report describes an anorexic behavior triggered by the simultaneous introduction of a novel diet and WR. This study examined the sequential, compared with the simultaneous, introduction of a novel high-fat (HF) diet and voluntary WR in rats of three different ages and revealed a surprising finding; the simultaneous introduction of HF food and voluntary WR induced a behavior in which the animals chose not to eat although food was available at all times. This phenomenon was apparently not due to an aversion to the novel HF diet because introduction of the running wheels plus the HF diet, while continuing the availability of the normal chow diet did not prevent the anorexia. Moreover, the anorexia was prevented with prior exposure to the HF diet. In addition, the anorexia was not related to extent of WR but dependent on the act of WR. The introduction a HF diet and locked running wheels did not induce the anorexia. This voluntary anorexia was accompanied by substantial weight loss, and the anorexia was rapidly reversed by removal of the running wheels. Moreover, the HF/WR-induced anorexia is preserved across the age span despite the intrinsic decrease in WR activity and increased consumption of HF food with advancing age. The described phenomenon provides a new model to investigate anorexia behavior in rodents.
anorexia; voluntary wheel running; high-fat feeding
Introduced species can alter the topology of food webs. For instance, an introduction can aid the arrival of free-living consumers using the new species as a resource, while new parasites may also arrive with the introduced species. Food-web responses to species additions can thus be far more complex than anticipated. In a subarctic pelagic food web with free-living and parasitic species, two fish species (arctic charr Salvelinus alpinus and three-spined stickleback Gasterosteus aculeatus) have known histories as deliberate introductions. The effects of these introductions on the food web were explored by comparing the current pelagic web with a heuristic reconstruction of the pre-introduction web. Extinctions caused by these introductions could not be evaluated by this approach. The introduced fish species have become important hubs in the trophic network, interacting with numerous parasites, predators and prey. In particular, five parasite species and four predatory bird species depend on the two introduced species as obligate trophic resources in the pelagic web and could therefore not have been present in the pre-introduction network. The presence of the two introduced fish species and the arrival of their associated parasites and predators increased biodiversity, mean trophic level, linkage density, and nestedness; altering both the network structure and functioning of the pelagic web. Parasites, in particular trophically transmitted species, had a prominent role in the network alterations that followed the introductions.
Electronic supplementary material
The online version of this article (doi:10.1007/s00442-012-2461-2) contains supplementary material, which is available to authorized users.
Non-native species; Pelagic community; Species additions; Topology; Trophic interactions
Background: Despite scarce scientific evidence, current feeding guidelines recommend delayed introduction of solids for the prevention of asthma and allergy.
Aims: To explore whether late introduction of solids is protective against the development of asthma, eczema, and atopy.
Methods: A total of 642 children were recruited before birth and followed to the age of 5½ years. Main outcome measures were: doctor's diagnosis of eczema ever, atopy according to skin prick test results against inhalant allergens, preschool wheezing, transient wheezing, all defined at age 5–5½ years. Introduction of solids as main exposure measure was assessed retrospectively at age 1 year.
Results: There was no evidence for a protective effect of late introduction of solids for the development of preschool wheezing, transient wheezing, atopy, or eczema. On the contrary, there was a statistically significant increased risk of eczema in relation to late introduction of egg (aOR 1.6, 95% CI 1.1 to 2.4) and milk (aOR 1.7, 95% CI 1.1 to 2.5). Late introduction of egg was furthermore associated with a non-significant increased risk of preschool wheezing (aOR 1.5, 95% CI 0.92 to 2.4). There was no statistical evidence of feeding practices playing a different role in the development of asthma and eczema after stratification for parental asthma and atopy status.
Conclusions: Results do not support the recommendations given by present feeding guidelines stating that a delayed introduction of solids is protective against the development of asthma and allergy.
The influence of introduction history and post-introduction dynamics on genetic diversity and structure has been a major research focus in invasion biology. However, genetic diversity and structure in the invasive range can also be affected by human-mediated processes in the native range prior to species introductions, an aspect often neglected in invasion biology. Here we aim to trace the native provenance of the invasive tree Acacia pycnantha by comparing the genetic diversity and structure between populations in the native Australian range and the invasive range in South Africa. This approach also allowed us to explore how human actions altered genetic structure before and after the introduction of A. pycnantha into South Africa. We hypothesized that extensive movement and replanting in A. pycnantha’s Australian range prior to its introduction to South Africa might result in highly admixed genotypes in the introduced range, comparable genetic diversity in both ranges, and therefore preclude an accurate determination of native provenance(s) of invasive populations.
In the native range Bayesian assignment tests identified three genetic clusters with substantial admixture and could not clearly differentiate previously identified genetic entities, corroborating admixture as a result of replantings within Australia. Assignment tests that included invasive populations from South Africa indicated similar levels of admixture compared to Australian populations and a lack of genetic structure. Invasive populations of A. pycnantha in South Africa are as genetically diverse as native populations, and could not be assigned to particular native range regions.
Our results indicate that the genetic structure of A. pycnantha in Australia has been greatly altered through various planting initiatives. Specifically, there is little geographic structure and high levels of admixture. While numerous introduction history scenarios may explain the levels of admixture observed in South Africa, planting records of A. pycnantha in Australia suggest that populations were probably already admixed before propagules were introduced to South Africa. These findings have important implications for the management of invasive A. pycnantha populations in South Africa, especially for classical biological control, and more broadly, for studies that aim to understand the evolutionary dynamics of the invasion process.
Acacia pycnantha; Admixture; Biological invasions; Genetic structure; Native range; Restoration; Wattle
White King pigeons exposed to food schedules before introduction of a colored photograph of a pigeon showed sustained schedule-induced attack on that image; additional birds given an early introduction to both the photograph and the schedule subsequently attacked the image at lower rates. Other pigeons attacked a second photograph of a pigeon regardless of whether it was introduced early or late. The late-introduction procedure was also effective in establishing attack on a projected image of a conspecific. The combined results showed that 14 of 17 White King pigeons given a late introduction to a pictorial target exhibited sustained attack against it and that a pigeon's initial reaction to a photograph of a conspecific when introduced early was a good predictor of subsequent schedule-induced attack on it.
A substantial part of vascular surgical workload is devoted to the treatment of varicose veins. To control demand for cosmetic venous surgery, primary care trusts in Somerset introduced clinical criteria in 2000 for the referral and treatment of varicose veins based on the presence of skin change or ulceration, a history of bleeding, or two or more episodes of thrombophlebitis.
PATIENTS AND METHODS
A comparison of workload and case mix for the referral and treatment of new patients presenting with varicose veins to the Taunton and Somerset Hospital was carried out over two 6-month periods, before and after the introduction of clinically based assessment criteria.
A total of 134 operations for varicose veins were carried out in 2000 and 85 such operations in 2002/03 after the introduction of new referral criteria (P = 0.001). Of these, 69% (92/134) were day-case procedures in 2000 compared to only 48% (41/85) in 2002/03 (P = 0.004). There was no significant difference in the type of cases (e.g. single, bilateral or recurrent surgery) performed as a day-case (P = 0.34) or as an in-patient (P = 0.43) over the two periods. There was, however, a significant difference (P = 0.007) in the mean ages of patients in the two periods (48.5 years in period 1; 57.8 years in period 2) and in the average ASA grade (1.15 in period 1; 1.42 in period 2; P = 0.0002).
The introduction of clinical criteria for the referral and treatment of varicose veins reduced workload by 37%.
Varicose veins; Management; Clinical criteria; Rationing
Since April 2002, collection and publication of surgeon-specific data in adult cardiac surgery has become mandatory in the UK. It has been suggested that this may discourage consultants from allowing trainees to perform cases. The aim of this study was to attempt to analyse the effect of the introduction of surgeon-specific data (SSD) on surgical training in a large cardiac surgical centre.
PATIENTS AND METHODS
A retrospective analysis was performed on 2111 consecutive patients undergoing elective coronary artery bypass surgery, aortic and mitral valve surgery at Southampton General Hospital between April 2000 and April 2004. Results were analysed and compared over a 2-year period prior to and a 2-year period following the introduction of SSD.
There were no changes in the overall mortality rate following the introduction of SSD. SSD was associated with a reduction in the overall proportion of cases performed by trainees (49% versus 42.8%; P = 0.004) and, in particular, a reduction in the proportion of aortic and mitral valve procedures performed by trainees. In addition, the proportion of cases performed by the trainees without consultant supervision declined significantly following SSD (18.7% versus 10.4%; P < 0.001).
Publication of surgeon-specific data has coincided with a decrease in both the proportion and variety of cases performed by trainees.
Cardiac surgery; Training
Performing a lumbar puncture in an unwell child can cause anxiety in both the parent and the junior doctor. There is increasing evidence of post‐lumbar‐puncture complications in this age group.
To improve the documentation, consent for and technical performance of paediatric lumbar punctures to 100% of the required standard within 3 months.
The paediatric emergency department of a the Royal North Shore Hospital (University of Sydney, Sydney, Australia).
Paediatric emergency staff, including residents, registrars and consultants.
Medical records of 40 consecutive children who had undergone a lumbar puncture in the 6 months before the introduction of the lumbar‐puncture proforma were reviewed. After introduction of the proforma, the records of 25 consecutive patients were reviewed to assess changes in the outcome measures. Before introduction of the proforma, junior medical staff were instructed in the procedure using specialised lumbar puncture manikins (Baby Stap; Laerdel, USA).
Before introduction of the proforma, the median number of documented indicators was 4, out of a maximum of 12. There was almost no documentation of parental consent, patient complications and analgesia. Introduction of the proforma resulted in a highly marked increase to a median of 12 documented indicators per patient (p<0.01, 95% confidence interval 6 to 8).
The introduction of a lumbar‐puncture proforma and formal teaching sessions using a paediatric manikin led to a marked improvement in the documentation of paediatric lumbar‐punctures. Lumbar‐punctures can be performed only by accredited medical officers who have achieved competency on the lumbar‐puncture teaching manikin.
Forty three patients with non-insulin dependent diabetes registered at two suburban practices were interviewed at least one year after the introduction of an organized general practice based system of diabetic surveillance and the results compared with data gathered from interviews administered before the introduction of the system. Structured data from the two interviews were compared in relation to the importance which patients attached to diabetes and its medical review, patients' preference for place of future review and the health professionals from whom they wished to receive diabetes care. Patients' ratings of the performance of health professionals on various aspects of care were compared with the ratings given before the introduction of the new service. At the follow-up interviews the reasons behind patients' responses to the structured questions were explored using a qualitative method. The introduction of a general practice based diabetes service was marked by an improvement in attendance for diabetes monitoring (56% before introduction, 98% in the year following introduction). This was associated with an increase in the importance which patients attached to diabetes and its medical review. After experience of diabetes care in general practice, patients remained enthusiastic about general practice involvement and confident in their general practitioners' knowledge about diabetes management. In spite of an improvement in the patients' ratings of hospital doctors' communication skills, they continued to rate general practitioners significantly more highly in these skills (P < 0.01) and in terms of convenience and accessibility (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
The introduction of species to areas beyond the limits of their natural distributions has a major homogenizing influence, making previously distinct biotas more similar. The scale of introductions has frequently been commented on, but their rate and spatial pervasiveness have been less well quantified. Here, we report the findings of a detailed study of pterygote insect introductions to Gough Island, one of the most remote and supposedly pristine temperate oceanic islands, and estimate the rate at which introduced species have successfully established. Out of 99 species recorded from Gough Island, 71 are established introductions, the highest proportion documented for any Southern Ocean island. Estimating a total of approximately 233 landings on Gough Island since first human landfall, this equates to one successful establishment for every three to four landings. Generalizations drawn from other areas suggest that this may be only one-tenth of the number of pterygote species that have arrived at the island, implying that most landings may lead to the arrival of at least one alien. These rates of introduction of new species are estimated to be two to three orders of magnitude greater than background levels for Gough Island, an increase comparable to that estimated for global species extinctions (many of which occur on islands) as a consequence of human activities.
Measurement of Stereopsis forms an important part of the clinical assessment of patients with disorders of ocular motility. The introduction of a real depth distance stereoacuity test (FD2) was evaluated in clinical practice and to what extent the introduction affected clinical management. Seventy-three patients under evaluation before and following the introduction of the test were included. Combined thresholds were measured at near using the Frisby and TNO test and at distance using the FD2. Fifty healthy controls were included. Forty-five patients demonstrated Stereopsis using the FD2 and 23 of these had a change in their management based in part on their responses using the FD2. Patients with evidence of Stereopsis using the FD2 were significantly more likely to have change in their management than expected from the whole sample (P = .02). The introduction of a real depth distance stereoacuity test into clinical practice contributed to a change in management when used in conjunction with other tests. The usefulness of the FD2 is limited by its range at 6 m. Use at closer distances necessitates the calculation of binocular threshold from the combined and monocular threshold.
Advances in the field of labour analgesia have tread a long journey from the days of ether and chloroform in 1847 to the present day practice of comprehensive programme of labour pain management using evidence-based medicine. Newer advances include introduction of newer techniques like combined spinal epidurals, low-dose epidurals facilitating ambulation, pharmacological advances like introduction of remifentanil for patient-controlled intravenous analgesia, introduction of newer local anaesthetics and adjuvants like ropivacaine, levobupivacaine, sufentanil, clonidine and neostigmine, use of inhalational agents like sevoflourane for patient-controlled inhalational analgesia using special vaporizers, all have revolutionized the practice of pain management in labouring parturients. Technological advances like use of ultrasound to localize epidural space in difficult cases minimizes failed epidurals and introduction of novel drug delivery modalities like patient-controlled epidural analgesia (PCEA) pumps and computer-integrated drug delivery pumps have improved the overall maternal satisfaction rate and have enabled us to customize a suitable analgesic regimen for each parturient. Recent randomized controlled trials and Cochrane studies have concluded that the association of epidurals with increased caesarean section and long-term backache remains only a myth. Studies have also shown that the newer, low-dose regimes do not have a statistically significant impact on the duration of labour and breast feeding and also that these reduce the instrumental delivery rates thus improving maternal and foetal safety. Advances in medical technology like use of ultrasound for localizing epidural space have helped the clinicians to minimize the failure rates, and many novel drug delivery modalities like PCEA and computer-integrated PCEA have contributed to the overall maternal satisfaction and safety.
Ambulatory epidurals; labour analgesia; recent advances
The objective of this study was to determine the safety and acceptability of the implementation of a day-case laparoscopic cholecystectomy (LC) service in a large UK teaching hospital, and analyse factors influencing contact with primary care providers. Wide-spread introduction of day-case LC in the UK is a major target of healthcare providers. However, few centres have reported their experience. In the US, out-patient surgery for LC has been reported, though many groups have utilised 24-h observation units to facilitate discharge. Concerns remain amongst surgeons regarding the feasibility and acceptability of the introduction of day-case LC in the UK.
PATIENTS AND METHODS
Comprehensive care and operative data were prospectively collected on the first 106 consecutive day-case procedures in our hospital. Postoperative recovery was monitored by telephone questionnaire on days 2, 5 and 14, including complications, satisfaction and general practitioner consultation.
A total of 106 patients were admitted for day-case LC, of whom 84% were discharged on the day of surgery. Patient satisfaction rate was 94% in both the successful day-case and the admitted patients. Mean operation time was 62 min, with an average total stay on the day-care unit of 426 min. Training-grade surgeons performed 31% of operations. Both the re-admission rate after surgery and rate of conversion to open surgery were 2%. Advice from primary healthcare providers was sought by 33% of patients within the first 14 postoperative days.
Introduction of day-case LC in the UK is feasible and acceptable to patients. The potential burden to primary care providers needs further study.
Cholecystectomy; Laparoscopic; Day-case
In 2004, an audit in our unit demonstrated wide variation in liver resection rates for colorectal cancer (CRC) metastases within the cancer network. Subsequently, a network-wide CT-based follow-up and referral policy was introduced for all patients. A second audit was performed to assess the impact of the guidelines on liver resection rates.
SUBJECTS AND METHODS
Analysis of prospective liver resection database between 1997 and 2004 and after the introduction of standardised guidelines between January 2005 and April 2008.
A total of 362 patients underwent liver resection for CRC metastases between 1997 and 2008, 237 prior to the introduction of the referral guidelines and 125 after. Liver resection rates according to referring hospital varied from 0.92 to 2.32 per 100,000 population before guidelines were introduced. After 2005, resection rates from the four district hospitals standardised (1.68–1.84 per 100,000 population), but the central unit rate (Sheffield) remained significantly higher (2.67 per 100,000 population). No significant difference in 1-year disease-free survival between patients from Sheffield and the outlying hospitals was found (P = 0.553).
Introduction of a referral protocol standardised resection rates from the four district hospitals, but these remain lower compared to the specialist centre. The wide-spread adoption of a policy to discuss all patients with liver metastases at an advanced disease multidisciplinary team meeting, in the presence of hepatobiliary specialists, may further increase resection rates across the UK.
Liver; surgery; Healthcare rationing; Colorectal cancer; Metastases
Understanding the dimensions of pathways of introduction of alien plants is important for regulating species invasions, but how particular pathways differ in terms of post-invasion success of species they deliver has never been rigorously tested. We asked whether invasion status, distribution and habitat range of 1,007 alien plant species introduced after 1500 A.D. to the Czech Republic differ among four basic pathways of introduction recognized for plants.
Pathways introducing alien species deliberately as commodities (direct release into the wild; escape from cultivation) result in easier naturalization and invasion than pathways of unintentional introduction (contaminant of a commodity; stowaway arriving without association with it). The proportion of naturalized and invasive species among all introductions delivered by a particular pathway decreases with a decreasing level of direct assistance from humans associated with that pathway, from release and escape to contaminant and stowaway. However, those species that are introduced via unintentional pathways and become invasive are as widely distributed as deliberately introduced species, and those introduced as contaminants invade an even wider range of seminatural habitats.
Pathways associated with deliberate species introductions with commodities and pathways whereby species are unintentionally introduced are contrasting modes of introductions in terms of invasion success. However, various measures of the outcome of the invasion process, in terms of species' invasion success, need to be considered to accurately evaluate the role of and threat imposed by individual pathways. By employing various measures we show that invasions by unintentionally introduced plant species need to be considered by management as seriously as those introduced by horticulture, because they invade a wide range of seminatural habitats, hence representing even a greater threat to natural areas.
The effect of food introduction timing on the development of food allergy remains controversial. We sought to examine whether the presence of childhood eczema changes the relationship between timing of food introduction and food allergy. The analysis includes 960 children recruited as part of a family-based food allergy cohort. Food allergy was determined by objective symptoms developing within 2 hours of ingestion, corroborated by skin prick testing/specific IgE. Physician diagnosis of eczema and timing of formula and solid food introduction were obtained by standardized interview. Cox Regression analysis provided hazard ratios for the development of food allergy for the same subgroups. Logistic regression models estimated the association of eczema and formula/food introduction with the risk of food allergy, individually and jointly. Of the 960 children, 411 (42.8%) were allergic to 1 or more foods and 391 (40.7%) had eczema. Children with eczema had a 8.4-fold higher risk of food allergy (OR, 95% CI: 8.4, 5.9–12.1). Among all children, later (>6 months) formula and rice/wheat cereal introduction lowered the risk of food allergy. In joint analysis, children without eczema who had later formula (OR, 95% CI: 0.5, 0.3–0.9) and later (>1 year) solid food (OR, 95% CI: 0.5, 0.3–0.95) introduction had a lower risk of food allergy. Among children with eczema, timing of food or formula introduction did not modify the risk of developing food allergy. Later food introduction was protective for food allergy in children without eczema but did not alter the risk of developing food allergy in children with eczema.
The early phases of biological invasions are poorly understood. In particular, during the introduction, establishment, and possible lag phases, it is unclear to what extent evolution must take place for an introduced species to transition from established to expanding. In this study, we highlight three disparate data sources that can provide insights into evolutionary processes associated with invasion success: biological control organisms, horticultural introductions, and natural history collections. All three data sources potentially provide introduction dates, information about source populations, and genetic and morphological samples at different time points along the invasion trajectory that can be used to investigate preadaptation and evolution during the invasion process, including immediately after introduction and before invasive expansion. For all three data sources, we explore where the data are held, their quality, and their accessibility. We argue that these sources could find widespread use with a few additional pieces of data, such as voucher specimens collected at certain critical time points during biocontrol agent quarantine, rearing, and release and also for horticultural imports, neither of which are currently done consistently. In addition, public access to collected information must become available on centralized databases to increase its utility in ecological and evolutionary research.
biological control; evolution; horticultural invasion; invasive species; lag phase; natural history collections; specimens
The introduction of non-native species into new habitats poses a major threat to native populations. Of particular interest, though often overlooked, are introductions of populations that are not fully reproductively isolated from native individuals and can hybridize with them. To address this important topic we used different approaches in a multi-pronged study, combining the effects of mate choice, shoaling behaviour and genetics. Here we present evidence that behavioural traits such as shoaling and mate choice can promote population mixing if individuals do not distinguish between native and foreign conspecifics. We examined this in the context of two guppy (Poecilia reticulata) populations that have been subject to an introduction and subsequent population mixing event in Trinidad. The introduction of Guanapo River guppies into the Turure River more than 50 years ago led to a marked reduction of the original genotype. In our experiments, female guppies did not distinguish between shoaling partners when given the choice between native and foreign individuals. Introduced fish are therefore likely to benefit from the protection of a shoal and will improve their survival chances as a result. The additional finding that male guppies do not discriminate between females on the basis of origin will further increase the process of population mixing, especially if males encounter mixed shoals. In a mesocosm experiment, in which the native and foreign populations were allowed to mate freely, we found, as expected on the basis of these behavioural interactions, that the distribution of offspring genotypes could be predicted from the proportions of the two types of founding fish. This result suggests that stochastic and environmental processes have reinforced the biological ones to bring about the genetic dominance of the invading population in the Turure River. Re-sampling the Turure for genetic analysis using SNP markers confirmed the population mixing process and showed that it is an on-going process in this river and has led to the nearly complete disappearance of the original genotype.
Treatment options for cerebral arteriovenous malformation (AVM) are still controversial due to the recent result of stereotactic radiosurgery and the improved result of microsurgical resection. We investigated previously treated AVM cases and discussed the efficacy and safety of preoperative embolization especially for microsurgical resection of high-grade AVM in the Spetzler-Martin grading.
Efficacy of preoperative embolization was evaluated based on 126 previously treated AVM cases at Shinshu University Hospital during the last 25 years. The safety of embolization was evaluated based on our previously-embolized 58 AVM cases (91 procedures) in the last 11 years after introduction of preoperative embolization for AVM. In all 126 cases, 82 were treated before introduction of embolization and 44 were treated after introduction of embolization. In 82 cases of the pre-embolization era, 63 lesions were removed totally in 63 AVMs (77%), partially resected in 11 (13%) and untreated in eight (10%). In 74 surgically removed cases, 11 (15%) cases showed severe intra/postoperative bleeding. In 44 cases of the embolization era, lesions were removed totally in 29 AVMs (66%), disappeared only with embolization in one (2%), disappeared with radiosurgery in seven (16%) and were untreated in five (11%). In 32 surgically removed cases, only one (2%) case showed severe intra/postoperative bleeding.
In all 58 embolized cases, 44 were surgically removed, six were treated with radiosurgery, one was eliminated with embolization alone and six were partially obliterated and followed up for their location. In 91 procedures for 58 cases, two haemorrhagic and three ischemic complications occurred, three were transient and two remained having neurological deficits.
The introduction of preoperative embolization improved the total removal rate and reduced the intra/postoperative bleeding rate in surgical removal of AVM. The total risk of embolization is low and well-designed preoperative embolization makes surgical resection safer even in high-grade AVM in the Spetzler-Martin grading.
arteriovenous malformation, embolization, surgery
Multiple origins indicate this serotype was introduced in several episodes.
Dengue virus serotype 4 (DENV-4) reemerged in Roraima State, Brazil, 28 years after it was last detected in the country in 1982. To study the origin and evolution of this reemergence, full-length sequences were obtained for 16 DENV-4 isolates from northern (Roraima, Amazonas, Pará States) and northeastern (Bahia State) Brazil during the 2010 and 2011 dengue virus seasons and for an isolate from the 1982 epidemic in Roraima. Spatiotemporal dynamics of DENV-4 introductions in Brazil were applied to envelope genes and full genomes by using Bayesian phylogeographic analyses. An introduction of genotype I into Brazil from Southeast Asia was confirmed, and full genome phylogeographic analyses revealed multiple introductions of DENV-4 genotype II in Brazil, providing evidence for >3 introductions of this genotype within the last decade: 2 from Venezuela to Roraima and 1 from Colombia to Amazonas. The phylogeographic analysis of full genome data has demonstrated the origins of DENV-4 throughout Brazil.
dengue virus; serotype 4; molecular epidemiology; phylogeography; Brazil; viruses; reemergence; genetic characterization; spatiotemporal patterns