100 research outputs found

    Patterns of Regeneration of Eastern White Pine (Pinus strobus L.) as Influenced by Large Isolated Reserve Trees and Precommercial Thinning

    Get PDF
    The spruce budworm epidemic of the 1970s and 1980s led to the salvage harvesting of spruce-fir stands, serving as a release for scattered immature eastern white pine (Pinus strobus L.) trees. These pines are now growing as large isolated reserve trees above a mixed conifer regeneration stratum. The objectives in this study were to determine any effect of varying levels of basal area (m2 ha-1) of large pine reserve trees may have on (1) the densities (stems ha-1) of both eastern white pine and non-pine species in the developing regeneration stratum, and (2) the height growth of eastern white pine in the developing regeneration stratum (3) incidence of white pine weevil injury of eastern white pine in the developing regeneration stratum, and (4) determine if any differences in quality exist between the two-aged stand type and the pre-commercially thinned stand type, relative to white pine weevil attack, blister rust infection, and branch shedding. Our null hypotheses were that large pine reserves have no effect on the density (stems ha-1) and height growth of the regenerating understory pine, or the density (stems ha-1) of the regenerating non-pine species, and also that large pine reserves have no effect on the frequency of white pine weevil injury of the regenerating understory pine, and that there were no differences in pine regeneration quality aspects between stand type. Thirteen forest stands throughout the spruce-fir region of Maine were chosen for this study. Nine of these stands were two-aged stands that were regenerated prior to 1995, have no history of pre-commercial thinning, and contain a significant component of heavily released eastern white pine trees growing above a developing mixed species matrix. These nine stands were harvested between the years of 1984 and 1994, and have soils ranging from somewhat poorly drained to very poorly drained. Four forest stands throughout the spruce-fir region of Maine that had been regenerated in the same time period as above, and also had a history of pre-commercial thinning that favored eastern white pine were also chosen for investigation in this study. One of these four stands contained a component of heavily released eastern white pine trees growing above the developing mixed species matrix. Soils ranged from poorly drained to very poorly-drained. Reserve pine basal area (m2 ha-1) was found to be positively correlated with the presence versus absence of pine in the regeneration stratum (p = 0.0398). The odds ratio of this model indicated that an increase of one square meter of reserve pine basal area increases the odds of pine regeneration success by 72 percent. This is true regardless of where reserve pine basal area (m2 ha-1) is held. Basal area (m2 ha-1) of reserve pine was not correlated with pine regeneration density (stems ha-1) when investigating only those plots in which pine regeneration was present (p = 0.2246). Non-pine density (stems ha-1) in the regeneration stratum was observed to be influenced more by differences in site, rather than basal area (m2 ha-1) of reserve pine trees. Reserve tree basal area (m2ha-1) was not significant in the model. Basal area of reserve pine (m ha ) had a negative (p = 0.0886) effect on mean annual height increment of pine regeneration. Basal area (m2 ha-1) of pine reserves was not correlated (p = 0.3721) with the presence versus absence of weevil injuries in the two-aged stand type. Likewise, pine reserve basal area (m2 ha-1) was not correlated with number of weevil injuries (p = 0.6950) when investigating only those plots in which weevil injuries were present. The two-aged stands with large isolated reserves were found to have lower incidence of weevil injury (p = 0.0055), with smaller weevil caused stem offsets (p = 0.0449). Two-aged stands also had smaller diameter branches (p = 0.0136). Incidence of white pine blister rust indicated caution should be used in the pre-commercially thinned stand type

    The Growth, Yield, and Financial Performance of Isolated Eastern White Pine (Pinus strobus L.) Reserve Trees

    Get PDF
    The ability of eastern white pine (Pinus strobus L.) to persist as emergent trees makes this species well suited to silvicultural systems in which they are retained as isolated reserves after a regeneration harvest. While such systems are implemented throughout the Acadian spruce-fir region of Maine, little is known about the growth response and financial performance of eastern white pine following complete release from competition. In this study, 77 trees from 8 sites throughout the Acadian spruce-fir region were sampled tree and crown measurements, and increment cores were extracted at breast height, as well as from the top of the valuable first 16 foot log. Volume growth was examined prior to and following release, and overall response to release was favorable. A subsample of 9 trees climbed to measure basal diameter and vertical location of each branch to develop allometric leaf area equations and to examine influence of site productivity and age on growth efficiency. Leaf area-volume increment relationships were modeled with a nonlinear power function with a random effect for site, and employed to forecast future growth. A sawmill simulator was used to estimate postrelease standing tree values and financial analysis was performed to assess performance of completely released trees for an unpruned and a hypothetical pruned scenario. Unpruned trees, on average exhibited peak net present value 52 years post-release. Pruned trees declined in net present value following release, due to high initial values. The net benefit of pruning reached its maximum 30 years after pruning, and stayed positive for 101 years, suggesting that pruning is a viable practice for eastern white pine that will be released and retained as reserve trees. The retention of eastern white pine reserve trees appears to be both biologically and financially sound, but forest managers should be careful to select vigorous younger trees as reserves to maximize financial performance

    Vernix caseosa peritonitis – no longer rare or innocent: a case series

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>Vernix Caseosa peritonitis is a rare post caesarean section complication with only 19 case reports in the literature to date. Vernix caseosa spilt at the time of caesarean section is thought to incite an inflammatory reaction, causing symptoms resembling an acute abdomen.</p> <p>Case Presentation</p> <p>We discuss three Caucasian patients (aged 32 to 43 years) who presented in our health sector in Sydney with vernix caseosa peritonitis. Each had a protracted course with significant comorbidities requiring surgical and medical intervention. This contrasts with other reports suggesting that a rapid resolution can be expected.</p> <p>This cluster may be a consequence of the rising caesarean section rate, a heightened local awareness of the condition and possibly a result of leaving material in the paracolic gutters intraoperatively.</p> <p>Conclusion</p> <p>Our aim is to increase awareness among our obstetric and surgical colleagues of the characteristic clinical presentation and intra-operative findings of vernix caseosa peritonitis. We also point out that, in contrast to those presented here, not all patients require laparotomy.</p

    Gene expression in cardiac tissues from infants with idiopathic conotruncal defects

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Tetralogy of Fallot (TOF) is the most commonly observed conotruncal congenital heart defect. Treatment of these patients has evolved dramatically in the last few decades, yet a genetic explanation is lacking for the failure of cardiac development for the majority of children with TOF. Our goal was to perform genome wide analyses and characterize expression patterns in cardiovascular tissue (right ventricle, pulmonary valve and pulmonary artery) obtained at the time of reconstructive surgery from 19 children with tetralogy of Fallot.</p> <p>Methods</p> <p>We employed genome wide gene expression microarrays to characterize cardiovascular tissue (right ventricle, pulmonary valve and pulmonary artery) obtained at the time of reconstructive surgery from 19 children with TOF (16 idiopathic and three with 22q11.2 deletions) and compared gene expression patterns to normally developing subjects.</p> <p>Results</p> <p>We detected a signal from approximately 26,000 probes reflecting expression from about half of all genes, ranging from 35% to 49% of array probes in the three tissues. More than 1,000 genes had a 2-fold change in expression in the right ventricle (RV) of children with TOF as compared to the RV from matched control infants. Most of these genes were involved in compensatory functions (e.g., hypertrophy, cardiac fibrosis and cardiac dilation). However, two canonical pathways involved in spatial and temporal cell differentiation (WNT, <it>p </it>= 0.017 and Notch, <it>p </it>= 0.003) appeared to be generally suppressed.</p> <p>Conclusions</p> <p>The suppression of developmental networks may represent a remnant of a broad malfunction of regulatory pathways leading to inaccurate boundary formation and improper structural development in the embryonic heart. We suggest that small tissue specific genomic and/or epigenetic fluctuations could be cumulative, leading to regulatory network disruption and failure of proper cardiac development.</p

    Vision in high-level football officials

    Get PDF
    YesOfficiating in football depends, at least to some extent, upon adequate visual function. However, there is no vision standard for football officiating and the nature of the relationship between officiating performance and level of vision is unknown. As a first step in characterising this relationship, we report on the clinically-measured vision and on the perceived level of vision in elite-level, Portuguese football officials. Seventy-one referees (R) and assistant referees (AR) participated in the study, representing 92% of the total population of elite level football officials in Portugal in the 2013/2014 season. Nine of the 22 Rs (40.9%) and ten of the 49 ARs (20.4%) were international-level. Information about visual history was also gathered. Perceived vision was assessed using the preference-values-assigned-to-global-visual-status (PVVS) and the Quality-of-Vision (QoV) questionnaire. Standard clinical vision measures (including visual acuity, contrast sensitivity and stereopsis) were gathered in a subset (n = 44, 62%) of the participants. Data were analysed according to the type (R/AR) and level (international/national) of official, and Bonferroni corrections were applied to reduce the risk of type I errors. Adopting criterion for statistical significance of p<0.01, PVVS scores did not differ between R and AR (p = 0.88), or between national- and international-level officials (p = 0.66). Similarly, QoV scores did not differ between R and AR in frequency (p = 0.50), severity (p = 0.71) or bothersomeness (p = 0.81) of symptoms, or between international-level vs national-level officials for frequency (p = 0.03) or bothersomeness (p = 0.07) of symptoms. However, international-level officials reported less severe symptoms than their national-level counterparts (p<0.01). Overall, 18.3% of officials had either never had an eye examination or if they had, it was more than 3 years previously. Regarding refractive correction, 4.2% had undergone refractive surgery and 23.9% wear contact lenses when officiating. Clinical vision measures in the football officials were similar to published normative values for young, adult populations and similar between R and AR. Clinically-measured vision did not differ according to officiating level. Visual acuity measured with and without a pinhole disc indicated that around one quarter of participants may be capable of better vision when officiating, as evidenced by better acuity (≥1 line of letters) using the pinhole. Amongst the clinical visual tests we used, we did not find evidence for above-average performance in elite-level football officials. Although the impact of uncorrected mild to moderate refractive error upon officiating performance is unknown, with a greater uptake of eye examinations, visual acuity may be improved in around a quarter of officials.Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013

    A large-scale genome-wide association study meta-analysis of cannabis use disorder

    Get PDF
    Summary Background Variation in liability to cannabis use disorder has a strong genetic component (estimated twin and family heritability about 50–70%) and is associated with negative outcomes, including increased risk of psychopathology. The aim of the study was to conduct a large genome-wide association study (GWAS) to identify novel genetic variants associated with cannabis use disorder. Methods To conduct this GWAS meta-analysis of cannabis use disorder and identify associations with genetic loci, we used samples from the Psychiatric Genomics Consortium Substance Use Disorders working group, iPSYCH, and deCODE (20 916 case samples, 363 116 control samples in total), contrasting cannabis use disorder cases with controls. To examine the genetic overlap between cannabis use disorder and 22 traits of interest (chosen because of previously published phenotypic correlations [eg, psychiatric disorders] or hypothesised associations [eg, chronotype] with cannabis use disorder), we used linkage disequilibrium score regression to calculate genetic correlations. Findings We identified two genome-wide significant loci: a novel chromosome 7 locus (FOXP2, lead single-nucleotide polymorphism [SNP] rs7783012; odds ratio [OR] 1·11, 95% CI 1·07–1·15, p=1·84 × 10−9) and the previously identified chromosome 8 locus (near CHRNA2 and EPHX2, lead SNP rs4732724; OR 0·89, 95% CI 0·86–0·93, p=6·46 × 10−9). Cannabis use disorder and cannabis use were genetically correlated (rg 0·50, p=1·50 × 10−21), but they showed significantly different genetic correlations with 12 of the 22 traits we tested, suggesting at least partially different genetic underpinnings of cannabis use and cannabis use disorder. Cannabis use disorder was positively genetically correlated with other psychopathology, including ADHD, major depression, and schizophrenia. Interpretation These findings support the theory that cannabis use disorder has shared genetic liability with other psychopathology, and there is a distinction between genetic liability to cannabis use and cannabis use disorder. Funding National Institute of Mental Health; National Institute on Alcohol Abuse and Alcoholism; National Institute on Drug Abuse; Center for Genomics and Personalized Medicine and the Centre for Integrative Sequencing; The European Commission, Horizon 2020; National Institute of Child Health and Human Development; Health Research Council of New Zealand; National Institute on Aging; Wellcome Trust Case Control Consortium; UK Research and Innovation Medical Research Council (UKRI MRC); The Brain & Behavior Research Foundation; National Institute on Deafness and Other Communication Disorders; Substance Abuse and Mental Health Services Administration (SAMHSA); National Institute of Biomedical Imaging and Bioengineering; National Health and Medical Research Council (NHMRC) Australia; Tobacco-Related Disease Research Program of the University of California; Families for Borderline Personality Disorder Research (Beth and Rob Elliott) 2018 NARSAD Young Investigator Grant; The National Child Health Research Foundation (Cure Kids); The Canterbury Medical Research Foundation; The New Zealand Lottery Grants Board; The University of Otago; The Carney Centre for Pharmacogenomics; The James Hume Bequest Fund; National Institutes of Health: Genes, Environment and Health Initiative; National Institutes of Health; National Cancer Institute; The William T Grant Foundation; Australian Research Council; The Virginia Tobacco Settlement Foundation; The VISN 1 and VISN 4 Mental Illness Research, Education, and Clinical Centers of the US Department of Veterans Affairs; The 5th Framework Programme (FP-5) GenomEUtwin Project; The Lundbeck Foundation; NIH-funded Shared Instrumentation Grant S10RR025141; Clinical Translational Sciences Award grants; National Institute of Neurological Disorders and Stroke; National Heart, Lung, and Blood Institute; National Institute of General Medical Sciences.Peer reviewe

    A large-scale genome-wide association study meta-analysis of cannabis use disorder

    Get PDF
    Background: Variation in liability to cannabis use disorder has a strong genetic component (estimated twin and family heritability about 50-70%) and is associated with negative outcomes, including increased risk of psychopathology. The aim of the study was to conduct a large genome-wide association study (GWAS) to identify novel genetic variants associated with cannabis use disorder. Methods: To conduct this GWAS meta-analysis of cannabis use disorder and identify associations with genetic loci, we used samples from the Psychiatric Genomics Consortium Substance Use Disorders working group, iPSYCH, and deCODE (20 916 case samples, 363 116 control samples in total), contrasting cannabis use disorder cases with controls. To examine the genetic overlap between cannabis use disorder and 22 traits of interest (chosen because of previously published phenotypic correlations [eg, psychiatric disorders] or hypothesised associations [eg, chronotype] with cannabis use disorder), we used linkage disequilibrium score regression to calculate genetic correlations. Findings: We identified two genome-wide significant loci: a novel chromosome 7 locus (FOXP2, lead single-nucleotide polymorphism [SNP] rs7783012; odds ratio [OR] 1·11, 95% CI 1·07-1·15, p=1·84 × 10-9) and the previously identified chromosome 8 locus (near CHRNA2 and EPHX2, lead SNP rs4732724; OR 0·89, 95% CI 0·86-0·93, p=6·46 × 10-9). Cannabis use disorder and cannabis use were genetically correlated (rg 0·50, p=1·50 × 10-21), but they showed significantly different genetic correlations with 12 of the 22 traits we tested, suggesting at least partially different genetic underpinnings of cannabis use and cannabis use disorder. Cannabis use disorder was positively genetically correlated with other psychopathology, including ADHD, major depression, and schizophrenia. Interpretation: These findings support the theory that cannabis use disorder has shared genetic liability with other psychopathology, and there is a distinction between genetic liability to cannabis use and cannabis use disorder

    How do minimum cigarette price laws affect cigarette prices at the retail level?

    No full text
    Objectives: Half of US states have minimum cigarette price laws that were originally passed to protect small independent retailers from unfair price competition with larger retailers. These laws prohibit cigarettes from being sold below a minimum price that is set by a formula. Many of these laws allow cigarette company promotional incentives offered to retailers, such as buydowns and master-type programmes, to be calculated into the formula. Allowing this provision has the potential to lower the allowable minimum price. This study assesses whether stores in states with minimum price laws have higher cigarette prices and lower rates of retailer participation in cigarette company promotional incentive programmes. Design: Retail cigarette prices and retailer participation in cigarette company incentive programmes in 2001 were compared in eight states with minimum price laws and seven states without them. New York State had the most stringent minimum price law at the time of the study because it excluded promotional incentive programmes in its price setting formula; cigarette prices in New York were compared to all other states included in the study. Results: Cigarette prices were not significantly different in our sample of US states with and without cigarette minimum price laws. Cigarette prices were significantly higher in New York stores than in the 14 other states combined. Conclusions: Most existing minimum cigarette price laws appear to have little impact on the retail price of cigarettes. This may be because they allow the use of promotional programmes, which are used by manufacturers to reduce cigarette prices. New York's strategy to disallow these types of incentive programmes may result in higher minimum cigarette prices, and should also be explored as a potential policy strategy to control cigarette company marketing practices in stores. Strict cigarette minimum price laws may have the potential to reduce cigarette consumption by decreasing demand through increased cigarette prices and reduced promotional activities at retail outlets
    • …
    corecore