Hybridization and adaptive radiation

Whether interspecific hybridization is important as a mechanism that generates biological diversity is a matter of controversy. Whereas some authors focus on the potential of hybridization as a source of genetic variation, functional novelty and new species, others argue against any important role, because reduced fitness would typically render hybrids an evolutionary dead end. By drawing on recent developments in the genetics and ecology of hybridization and on principles of ecological speciation theory, I develop a concept that reconciles these views and adds a new twist to this debate. Because hybridization is common when populations invade new environments and potentially elevates rates of response to selection, it predisposes colonizing populations to rapid adaptive diversification under disruptive or divergent selection. I discuss predictions and suggest tests of this hybrid swarm theory of adaptive radiation and review published molecular phylogenies of adaptive radiations in light of the theory. Some of the confusion about the role of hybridization in evolutionary diversification stems from the contradiction between a perceived necessity for cessation of gene flow to enable adaptive population differentiation on the one hand [1], and the potential of hybridization for generating adaptive variation, functional novelty and new species 2, 3 and 4 on the other. Much progress in the genetics 5, 6, 7, 8 and 9 and ecology of hybridization 9, 10 and 11, and in our understanding of the role of ecology in speciation (see Glossary) 12, 13 and 14 make a re-evaluation timely. Whereas botanists traditionally stressed the diversity-generating potential of hybridization 2, 3 and 14, zoologists traditionally saw it as a process that limits diversification [1] and refer to it mainly in the contexts of hybrid zones (Box 1) and reinforcement of reproductive isolation [15]. Judging by the wide distribution of allopolyploidy among plants, many plant species might be of direct hybrid origin or descended from a hybrid species in the recent past [16]. The ability to reproduce asexually might explain why allopolyploid hybrid species are more common in plants than in animals. Allopolyploidy arises when meiotic mismatch of parental chromosomes or karyotypes causes hybrid sterility. Mitotic error, duplicating the karyotype, can restore an asexually maintained hybrid line to fertility. Although bisexual allopolyploid hybrid species are not uncommon in fish [17] and frogs [18], the difficulty with which allopolyploid animals reproduce, typically requiring gynogenesis[19], makes establishment and survival of allopolyploid animal species difficult.

Evaluation of a date rape prevention program for new students in a university setting

The purpose of this study was to design, implement and evaluate the effectiveness of a date rape prevention program among new students at Rice University. Six-hundred and fifteen new students were randomly assigned to one of eight residential colleges or dormitories. The distribution of students to each of the dormitories was carried out in accordance with a stratified random sampling procedure. The study population was divided into strata based on ethnicity, gender, geographical region, and academic major. The number of students randomly assigned to each of the eight dormitories was approximately 75. After this procedure was completed, each of the colleges was randomly selected to either the intervention or control group. A randomized pretest and posttest control group design was used to assess changes in attitudes, self-efficacy, and behavior with regard to date rape. All participants were given an anonymous pretest and posttest measuring attitudes, self-efficacy, and behavior immediately prior to and following the intervention. The intervention group attended the play Scruples, designed to promote date rape prevention, after which they were immediately posttested. After this initial posttest the intervention group also participated in an interactive group role-playing activity led by trained peer instructors. The control group was pretested and subject to the placebo intervention of a multiculturalism play and was posttested immediately afterwards. Later in the week this group saw the Scruples play only. Both control and intervention groups were sent a two month follow-up survey questionnaire, to measure any changes in attitudes, self-efficacy, and behavior over time. As hypothesized students who saw the play Scruples showed a change in attitudes immediately posttest but no difference in self-efficacy or behavior. The two month follow-up survey showed no change in attitudes, self-efficacy, or behavior. There was a difference at pretest in males and females attitudes, with males showing significantly more rape tolerant attitudes than females. Thus, the proposed research findings will provide a better understanding of the attitudes that perpetuate date rape, and will inform strategies for prevention programs. ^

New Philology and the Biogenetics of Texts

The discussion on the New Philology triggered by French and North American scholars in the last decade of the 20th century emphasized the material character of textual transmission inside and outside the written evidences of medieval manuscripts by downgrading the active role of the historical author. However, the reception of the ideas propagated by the New Philology adherents was rather divided. Some researchers considered it to be the result of an academic “crisis” (R.T. Pickens) or questioned its innovative status (K. Stackmann: “Neue Philologie?”); others appreciated the “new attitudes to the page” it had brought to mind (J. Bumke after R.H. and M.A, Rouse) or even saw a new era of the “powers of philology” evoked (H.-U. Gumbrecht). Besides the debates on the New Philology another concept of textual materiality strengthened in the last decade, maintaining that textual alterations somewhat relate to biogenetic mutations. In a matter of fact, phenomena such as genetic and textual variation, gene recombination and ‘contamination’ (the mixing of different exemplars in one manuscript text) share common features. The paper discusses to what extent the biogenetic concepts can be used for evaluating manifestations of textual production (as the approach of ‘critique génétique’ does) and of textual transmission (as the phylogenetic analysis of manuscript variation does). In this context yet the genealogical concept of stemmatology – the treelike representation of textual development abhorred by the New Philology adepts – might prove to be useful for describing the history of texts. The textual material to be analyzed will be drawn from the Parzival Project, which is currently preparing a new electronic edition of Wolfram von Eschenbach’s Parzival novel written shortly after 1200 and transmitted in numerous manuscripts up to the age of printing. Researches of the project have actually resulted in suggesting that the advanced knowledge of the manuscript transmission yields a more precise idea on the author’s own writing process.

Ecosystem functions are resistant to extreme changes to rainfall regimes in a mesotrophic grassland

Major changes to rainfall regimes are predicted for the future but the effect of such changes on terrestrial ecosystem function is largely unknown. We created a rainfall manipulation experiment to investigate the effects of extreme changes in rainfall regimes on ecosystem functioning in a grassland system. We applied two rainfall regimes; a prolonged drought treatment (30 % reduction over spring and summer) and drought/downpour treatment (long periods of no rainfall interspersed with downpours), with an ambient control. Both rainfall manipulations included increased winter rainfall. We measured plant community composition, CO2 fluxes and soil nutrient availability. Plant species richness and cover were lower in the drought/downpour treatment, and showed little recovery after the treatment ceased. Ecosystem processes were less affected, possibly due to winter rainfall additions buffering reduced summer rainfall, which saw relatively small soil moisture changes. However, soil extractable P and ecosystem respiration were significantly higher in rainfall change treatments than in the control. This grassland appears fairly resistant, in the short term, to even the more extreme rainfall changes that are predicted for the region, although prolonged study is needed to measure longer-term impacts. Differences in ecosystem responses between the two treatments emphasise the variety of ecosystem responses to changes in both the size and frequency of rainfall events. Given that model predictions are inconsistent there is therefore a need to assess ecosystem function under a range of potential climate change scenarios.

The Transmission of Manuscripts and the Genetics of Texts. A new critical edition of Wolfram von Eschenbach’s Parzival

The discussion on the New Philology triggered by French and North American scholars in the last decade of the 20th century emphasized the material character of textual transmission inside and outside the written evidences of medieval manuscripts by downgrading the active role of the historical author. However, the reception of the ideas propagated by the New Philology adherents was rather divided. Some researchers questioned its innovative status (K. Stackmann: “Neue Philologie?”), others saw a new era of the “powers of philology” evoked (H.-U. Gumbrecht). Besides the debates on the New Philology another concept of textual materiality strengthened in the last decade, maintaining that textual alterations somewhat relate to biogenetic mutations. In a matter of fact, phenomena such as genetic and textual variation, gene recombination and ‘contamination’ (the mixing of different exemplars in one manuscript text) share common features. The paper discusses to what extent the biogenetic concepts can be used for evaluating manifestations of textual production (as the approach of ‘critique génétique’ does) and of textual transmission (as the phylogenetic analysis of manuscript variation does). In this context yet the genealogical concept of stemmatology – the treelike representation of textual development abhorred by the New Philology adepts – might prove to be useful for describing the history of texts. The textual material to be analyzed will be drawn from the Parzival Project, which is currently preparing a new electronic edition of Wolfram von Eschenbach’s Parzival novel written shortly after 1200 and transmitted in numerous manuscripts up to the age of printing (www.parzival.unibe.ch). Researches of the project have actually resulted in suggesting that the advanced knowledge of the manuscript transmission yields a more precise idea on the author’s own writing process.

CT coronary angiography versus conventional invasive coronary angiography - the view of the referring physician

PURPOSE Assessment of experience gained by local referring physicians with the procedure of coronary computed tomographic angiography (CCTA) in the everyday clinical routine. MATERIALS AND METHODS A 25-item questionnaire was sent to 179 physicians, who together had referred a total of 1986 patients for CCTA. They were asked about their experience to date with CCTA, the indications for coronary imaging, and their practice in referring patients for noninvasive CCTA or invasive catheter angiography. RESULTS 53 questionnaires (30 %) were assessable, corresponding to more than 72 % of the patients referred. Of the referring physicians who responded, 94 % saw a concrete advantage of CCTA in the treatment of patients, whereby 87 % were 'satisfied' or 'very satisfied' with the reporting. For excluding coronary heart disease (CHD) where there was a low pre-test probability of disease, the physicians considered CCTA to be superior to conventional coronary diagnosis (4.2 on a scale of 1 - 5) and vice versa for acute coronary syndrome (1.6 of 5). The main reasons for unsuitability of CCTA for CT diagnosis were claustrophobia and the absence of a sinus rhythm. The level of exposure to radiation in CCTA was estimated correctly by only 42 % of the referring physicians. 90 % of the physicians reported that their patients evaluated their coronary CT overall as 'positive' or 'neutral', while 87 % of the physicians whose patients had undergone both procedures reported that the patients had experienced CCTA as the less disagreeable of the two. CONCLUSION CCTA is accepted by the referring physicians as an alternative imaging procedure for the exclusion of CHD and received a predominantly positive assessment from both the referring physicians and the patients.

Visual avoidance in phobia: particularities in neural activity, autonomic responding, and cognitive risk evaluations.

We investigated the neural mechanisms and the autonomic and cognitive responses associated with visual avoidance behavior in spider phobia. Spider phobic and control participants imagined visiting different forest locations with the possibility of encountering spiders, snakes, or birds (neutral reference category). In each experimental trial, participants saw a picture of a forest location followed by a picture of a spider, snake, or bird, and then rated their personal risk of encountering these animals in this context, as well as their fear. The greater the visual avoidance of spiders that a phobic participant demonstrated (as measured by eye tracking), the higher were her autonomic arousal and neural activity in the amygdala, orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), and precuneus at picture onset. Visual avoidance of spiders in phobics also went hand in hand with subsequently reduced cognitive risk of encounters. Control participants, in contrast, displayed a positive relationship between gaze duration toward spiders, on the one hand, and autonomic responding, as well as OFC, ACC, and precuneus activity, on the other hand. In addition, they showed reduced encounter risk estimates when they looked longer at the animal pictures. Our data are consistent with the idea that one reason for phobics to avoid phobic information may be grounded in heightened activity in the fear circuit, which signals potential threat. Because of the absence of alternative efficient regulation strategies, visual avoidance may then function to down-regulate cognitive risk evaluations for threatening information about the phobic stimuli. Control participants, in contrast, may be characterized by a different coping style, whereby paying visual attention to potentially threatening information may help them to actively down-regulate cognitive evaluations of risk.

Proximal Femoral Osteotomies with the Paediatric Hip Plate (LCP): Valgus osteotomy.

OBJECTIVE Proximal femoral osteotomy with stable fixation and sufficient correction. Low complication rates due to exact preoperative planning. INDICATIONS Congenital or traumatic femoral neck pseudarthrosis. Coxa vara. CONTRAINDICATIONS None. In severe deformities, a single femoral osteotomy may not solve the problem; thus, additional correction, e.g., a pelvic osteotomy, is required. SURGICAL TECHNIQUE Correct planning of the correction angle. Lateral approach. Subperiosteal detachment of vastus lateralis muscle. Place guide wire on the femoral neck to judge anteversion. Insert positioning wire 5 mm distal to trochanteric physis. Insert 2.8 mm Kirschner wire in the femoral neck. Osteotomy of the femur after marking the rotation by Kirschner wires or oscillating saw. Slide LC plate over Kirschner wires. Replace Kirschner wires with screws. Reduction of the femoral shaft to the plate with bone forceps. Definitive fixation of the plate to the femoral shaft by cortex or locking screws. Readaptation of vastus lateralis muscle over the plate. POSTOPERATIVE MANAGEMENT Partial weightbearing for 4-6 weeks depending on the age of the patient without any external fixation (e. g. cast) is possible. RESULTS Recent studies support the authors' findings of sufficient correction and stable fixation after proximal femoral osteotomy with the LCP pediatric hip plate. Low complication rates and stable fixation.

The European Registry for Patients with Mechanical Circulatory Support (EUROMACS): first annual report

The European Registry for Patients with Mechanical Circulatory Support (EUROMACS) was founded on 10 December 2009 with the initiative of Roland Hetzer (Deutsches Herzzentrum Berlin, Berlin, Germany) and Jan Gummert (Herz- und Diabeteszentrum Nordrhein-Westfalen, Bad Oeynhausen, Germany) with 15 other founding international members. It aims to promote scientific research to improve care of end-stage heart failure patients with ventricular assist device or a total artificial heart as long-term mechanical circulatory support. Likewise, the organization aims to provide and maintain a registry of device implantation data and long-term follow-up of patients with mechanical circulatory support. Hence, EUROMACS affiliated itself with Dendrite Clinical Systems Ltd to offer its members a software tool that allows input and analysis of patient clinical data on a daily basis. EUROMACS facilitates further scientific studies by offering research groups access to any available data wherein patients and centres are anonymized. Furthermore, EUROMACS aims to stimulate cooperation with clinical and research institutions and with peer associations involved to further its aims. EUROMACS is the only European-based Registry for Patients with Mechanical Circulatory Support with rapid increase in institutional and individual membership. Because of the expeditious data input, the European Association for Cardiothoracic Surgeons saw the need to optimize the data availability and the significance of the registry to improve care of patients with mechanical circulatory support and its potential contribution to scientific intents; hence, the beginning of their alliance in 2012. This first annual report is designed to provide an overview of EUROMACS' structure, its activities, a first data collection and an insight to its scientific contributions.

Follow-up care of young childhood cancer survivors: attendance and parental involvement.

PURPOSE Despite recommendations, only a proportion of long-term childhood cancer survivors attend follow-up care. We aimed to (1) describe the follow-up attendance of young survivors aged 11-17 years; (2) describe the parental involvement in follow-up, and (3) investigate predictors of follow-up attendance and parental involvement. METHODS As part of the Swiss Childhood Cancer Survivor Study, a follow-up questionnaire was sent to parents of childhood cancer survivors aged 11-17 years. We assessed follow-up attendance of the child, parents' involvement in follow-up, illness perception (Brief IPQ), and sociodemographic data. Clinical data was available from the Swiss Childhood Cancer Registry. RESULTS Of 309 eligible parents, 189 responded (67 %; mean time since diagnosis 11.3 years, range 6.8-17.2) and 75 % (n = 141) reported that their child still attended follow-up. Of these, 83 % (n = 117) reported ≥1 visit per year and 17 % (n = 23) reported <1 visit every year. Most survivors saw pediatric oncologists (n = 111; 79 % of 141), followed by endocrinologists (n = 24, 17 %) and general practitioners (n = 22, 16 %). Most parents (92 %) reported being involved in follow-up (n = 130). In multivariable and Cox regression analyses, longer time since diagnosis (p = 0.025) and lower perceived treatment control (assessed by IPQ4: how much parents thought follow-up can help with late effects; p = 0.009) were associated with non-attendance. Parents' overall information needs was significantly associated with parental involvement in the multivariable model (p = 0.041). CONCLUSION Educating survivors and their parents on the importance and effectiveness of follow-up care might increase attendance in the longer term.

Production Streamlining through Design, Implementation, and Analysis of Lean Manufacturing Methods

Through the correct implementation of lean manufacturing methods, a company can greatly improve their business. Over a period of three months at TTM Technologies, I utilized my knowledge to fix existing problems ans streamline production. In addition, other trouble areas in their production process were discovered and proper lean methods were used to address them. TTM Technologies saw many changed in the right direction over this time period.

Role of entorhinal cortical plasticity in spatial and contextual memory

It is well accepted that the hippocampus (HIP) is important for spatial and contextual memories, however, it is not clear if the entorhinal cortex (EC), the main input/output structure for the hippocampus, is also necessary for memory storage. Damage to the EC in humans results in memory deficits. However, animal studies report conflicting results on whether the EC is necessary for spatial and contextual memory. Memory consolidation requires gene expression and protein synthesis, mediated by signaling cascades and transcription factors. Extracellular-signal regulated kinase (ERK) cascade activity is necessary for long-term memory in several tasks, including those that test spatial and contextual memory. In this work, we explore the role of ERK-mediated plasticity in the EC on spatial and contextual memory. ^ To evaluate this role, post-training infusions of reversible pharmacological inhibitors specific for the ERK cascade that do not affect normal neuronal activity were targeted directly to the EC of awake, behaving animals. This technique provides spatial and temporal control over the inhibition of the ERK cascade without affecting performance during training or testing. Using the Morris water maze to study spatial memory, we found that ERK inhibition in the EC resulted in long-term memory deficits consistent with a loss of spatial strategy information. When animals were allowed to learn and consolidate a spatial strategy for solving the task prior to training and ERK inhibition, the deficit was alleviated. To study contextual memory, we trained animals in a cued fear-conditioning task and saw an increase in the activation of ERK in the EC 90 minutes following training. ERK inhibition in the EC over this time point, but not at an earlier time point, resulted in increased freezing to the context, but not to the tone, during a 48-hour retention test. In addition, animals froze maximally at the time the shock was given during training; similar to naïve animals receiving additional training, suggesting that ERK-mediated plasticity in the EC normally suppresses the temporal nature of the freezing response. These findings demonstrate that plasticity in the EC is necessary for both spatial and contextual memory, specifically in the retention of behavioral strategies. ^

The effect of triage team on time-in-department in a pediatric emergency department

Objective. To determine whether the use of a triage team would reduce the average time-in-department in a pediatric emergency department by 25%.^ Methods. A triage team consisting of a physician, a nurse, and a nurse's assistant initiated work-ups and saw patients who required minimal lab work-up and were likely to be discharged. Study days were randomized. Our inclusion criteria were all children seen in the emergency center between 6p and 2a Monday-Friday. Our exclusion criteria included resuscitations, inpatient-inpatient transfers, left without being seen, leaving against medical advice, any child seen outside of 6p-2am Monday-Friday and on the weekends. A Pearson-Chi square was used for comparison of the two groups for heterogeneity. For the time-in-department analysis, we performed a 2 sided t-test with a set alpha of 0.05 using Mann Whitney U looking for differences in time-in-department based on acuity level, disposition, and acuity level stratified by disposition. ^ Results. Among urgent and non-urgent patients, we found a statistically significant decrease in time-in-department in a pediatric emergency department. Urgent patients had a time-in-department that was 51 minutes shorter than patients seen on non-triage team days (p=0.007), which represents a 14% decrease in time-in-department. Non-urgent patients seen on triage team days had a time-in-department that was 24 minutes shorter than non-urgent patients seen on non-triage team days (p=0.009). From the disposition perspective, discharged patients seen on triage team days had a shorter time-in-department of 28 minutes as compared to those seen on non-triage team days (p=0.012). ^ Conclusion. Overall, there was a trend towards decreased time-in-department of 19 minutes (5.9% decrease) during triage team times. There was a statistically significant decrease in the time-in-department among urgent patients of 51 minutes (13.9% decrease) and among discharged patients of 28 minutes (8.4% decrease). Urgent care patients make up nearly a quarter of the emergency patient population and decreasing their time-in-department would likely make a significant impact on overall emergency flow.^

Prevalence and trends of substance abuse in Harris County, Texas, 1989 to 1991

In the late 1980s, Harris County, Texas began experiencing an escalation of drug-related activities. Various indicators used in this analysis tracked drug-related trends from 1989 to 1991 to determine patterns for comparison of local (Houston/Harris County, Texas) to national levels.^ An important indicator of the drug scenario was drug-related activities among youths, which increased during the period of this study. The Harris County Juvenile Probation Department showed that among arrests for drug-related activities, felonies increased from 25% in 1988 to 53% in 1991. With the rise in drug-related crimes, and substance abuse among the student body, school districts were forced to institute drug education programs in an effort to curtail such activities.^ Law enforcement agencies in the county saw increased demands for their services as a result of drug activities. Harris County Sheriffs Department reported a 32% plus increase in drug-related charges between 1986 and 1991. Houston Police Department reported an increase of 109% for the same period.^ Data from the Harris County Medical Examiner, the National Institute of Justice's Drug Use Forecasting System (Houston), and drug treatment facilities around Houston/Harris County, Texas indicated similar drug usage trends. Over a four-year period (1988-91), the drugs most frequently detected during blood and urine analyses were cocaine, followed by marijuana, heroin, LSD, and methamphetamines.^ From 1988 to 1991, most drug rehabilitation organizations experienced increased demands for their services by approximately 35%. Several other organizations experienced as much as a 70 percent increase. Males accounted for roughly 70% and females about 30% of persons seeking treatment. However, the number of females pursuing treatment increased, thereby reducing the gender gap.^ Blacks in Houston/Harris County were at higher risk for drug usage among the general population, but sought treatment more readily than other ethnic groups. Whites sought treatment in similar numbers as Blacks, but overall the risk appeared smaller because they made up a larger portion of the Houston/Harris County population.^ This analysis concluded that drug trends for the Houston/Harris County, Texas did not follow national trends, but showed patterns of its own. It was recommended that other communities carry out similar studies to determine drug use trends particular to their local. ^

ECONOMIC ANALYSIS OF THE DEMAND FOR PRESCRIPTION MEDICINE IN THE UNITED STATES

The purpose of this study was to understand the role of principle economic, sociodemographic and health status factors in determining the likelihood and volume of prescription drug use. Econometric demand regression models were developed for this purpose. Ten explanatory variables were examined: family income, coinsurance rate, age, sex, race, household head education level, size of family, health status, number of medical visits, and type of provider seen during medical visits. The economic factors (family income and coinsurance) were given special emphasis in this study.^ The National Medical Care Utilization and Expenditure Survey (NMCUES) was the data source. The sample represented the civilian, noninstitutionalized residents of the United States in 1980. The sample method used in the survey was a stratified four-stage, area probability design. The sample was comprised of 6,600 households (17,123 individuals). The weighted sample provided the population estimates used in the analysis. Five repeated interviews were conducted with each household. The household survey provided detailed information on the United States health status, pattern of health care utilization, charges for services received, and methods of payments for 1980.^ The study provided evidence that economic factors influenced the use of prescription drugs, but the use was not highly responsive to family income and coinsurance for the levels examined. The elasticities for family income ranged from -.0002 to -.013 and coinsurance ranged from -.174 to -.108. Income has a greater influence on the likelihood of prescription drug use, and coinsurance rates had an impact on the amount spent on prescription drugs. The coinsurance effect was not examined for the likelihood of drug use due to limitations in the measurement of coinsurance. Health status appeared to overwhelm any effects which may be attributed to family income or coinsurance. The likelihood of prescription drug use was highly dependent on visits to medical providers. The volume of prescription drug use was highly dependent on the health status, age, and whether or not the individual saw a general practitioner. ^