Silviculture alters the genetic structure of an eastern hemlock forest in Maine, USA

2005 ◽  
Vol 35 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Gary J Hawley ◽  
Paul G Schaberg ◽  
Donald H DeHayes ◽  
John C Brissette
Keyword(s):  
Genetic Structure ◽  
Environmental Change ◽  
Tsuga Canadensis ◽  
Allelic Frequency ◽  
Eastern Hemlock ◽  
Control Group ◽  
Unique Gene ◽  
Genetic Potential ◽  
Rare Alleles

We evaluated the influence of long-term silvicultural selection on the genetic structure of an eastern hemlock (Tsuga canadensis (L.) Carr.) forest at the Penobscot Experimental Forest, in Maine, USA. Plots in this forest received one of the following three treatments: (1) selection cuts in which small and poorly formed trees were preferentially removed in 1957 and 1977; (2) diameter-limit cuts in which trees at least 24 cm in diameter were removed in 1952, 1973, and 1994; or (3) no harvesting (an unmanaged control). Because of an association between the occurrence of rare alleles and tree phenotypes, phenotypically based tree removals were associated with a shift in allelic frequency. Where smaller trees with inferior phenotypes were preferentially removed (selection cut), the number of rare alleles and estimates of future genetic potential were lower than in the control group. Because of the theoretical long-term evolutionary benefit of unique gene forms, the loss of rare alleles could diminish the potential of populations to adapt to and survive ongoing environmental change. In contrast, alleles that were rare in the control group existed at a higher frequency in the diameter-limit cut. However, productivity was low in this stand, where the frequency of characteristically rare alleles was artificially amplified.

scholarly journals Experiments Are Revealing a Foundation Species: A Case Study of Eastern Hemlock (Tsuga canadensis)

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Aaron M. Ellison
Keyword(s):  
Energy Flux ◽  
Large Scale ◽  
Regional Climate ◽  
Ecosystem Processes ◽  
Tsuga Canadensis ◽  
Foundation Species ◽  
Eastern Hemlock ◽  
Long Term Effects ◽  
Large Measure

Foundation species are species that create and define particular ecosystems; control in large measure the distribution and abundance of associated flora and fauna; and modulate core ecosystem processes, such as energy flux and biogeochemical cycles. However, whether a particular species plays a foundational role in a system is not simply asserted. Rather, it is a hypothesis to be tested, and such tests are best done with large-scale, long-term manipulative experiments. The utility of such experiments is illustrated through a review of the Harvard Forest Hemlock Removal Experiment (HF-HeRE), a multidecadal, multihectare experiment designed to test the foundational role of eastern hemlock, Tsuga canadensis, in eastern North American forests. Experimental removal of T. canadensis has revealed that after 10 years, this species has pronounced, long-term effects on associated flora and fauna, but shorter-term effects on energy flux and nutrient cycles. We hypothesize that on century-long scales, slower changes in soil microbial associates will further alter ecosystem processes in T. canadensis stands. HF-HeRE may indeed continue for >100 years, but at such time scales, episodic disturbances and changes in regional climate and land cover can be expected to interact in novel ways with these forests and their foundation species.

scholarly journals Treatment Strategies Using Imidacloprid in Hemlock Woolly Adelgid (Adelges tsugae Annand) Infested Eastern Hemlock (Tsuga canadensis Carrière) Trees

2012 ◽  
Vol 38 (2) ◽  
pp. 41-49
Author(s):  
Joseph Doccola ◽  
William Hascher ◽  
John Aiken ◽  
Peter Wild
Keyword(s):  
Vascular System ◽  
Large Diameter ◽  
Treatment Strategies ◽  
Tsuga Canadensis ◽  
Hemlock Woolly Adelgid ◽  
Adelges Tsugae ◽  
Eastern Hemlock ◽  
Upward Movement ◽  
Neonicotinoid Insecticide

Due to the widespread establishment of hemlock woolly adelgid (Adelges tsugae Annand) (HWA) across the range of eastern hemlock (Tsuga canadensis Carriere), woodland trees may be infested for many years before treatment is made. Symptoms of prolonged infestation include extensive dieback and thinned canopies. Imidacloprid, a systemic neonicotinoid insecticide, is a useful and effective tool to manage HWA. In this study, mature, large diameter trees in poor condition were treated with imidacloprid. Trees were treated once by trunk and/or soil injection in Asheville, North Carolina, U.S. Following application, changes in tree growth, HWA density and imidacloprid residues were measured for three years. Trees treated with imidacloprid recovered, whereas the untreated trees continued to struggle. Trees injected with imidacloprid accumulated compound in the canopy, facilitating refoliation and the imidacloprid persisted for three years. This extended activity of trunk-injected imidacloprid was attributed in part to slow upward movement through the restrictive tracheid vascular system and to perennial needle retention. The imidacloprid soil injection was slower to act systemically, but has potential for longer-term activity. Researchers suggest the combination of tree and soil injection for immediate and long-term (4+ years) activity as an effective and economic strategy to protect high-value trees.

The response of skin perfusion and of rheological and immunological variables to intravenous prostanoid administration in Raynaud’s phenomenon secondary to collagenosis

VASA ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 243-249 ◽  
Author(s):  
Drinda ◽  
Neumann ◽  
Pöhlmann ◽  
Vogelsang ◽  
Stein ◽  
...  
Keyword(s):  
Laser Doppler Flowmetry ◽  
Raynaud’S Phenomenon ◽  
Raynaud's Phenomenon ◽  
Plasma Viscosity ◽  
Laser Doppler ◽  
Erythrocyte Aggregation ◽  
Control Group ◽  
Long Term Effects ◽  
Doppler Flowmetry

Background: Prostanoids are used in the treatment of Raynaud’s phenomenon and acral perfusion disorders secondary to collagenosis. In subjective terms, intravenous administration of these agents produces success in more than 50% of patients. The therapeutic outcome of clinical administration of alprostadil or iloprost may vary from individual to individual. Patients and methods: The following variables were analysed in a cross-over study in 27 patients with collagenosis and Raynaud’s phenomenon: plasma viscosity and erythrocyte aggregation (rheological variables), partial pressure of oxygen and laser Doppler flowmetry in the finger region, and lymphocyte phenotyping and interleukin (IL) determinations (immunological variables). Results: Laser Doppler flowmetry revealed significant differences between patients with secondary Raynaud’s phenomenon and a control group of 25 healthy subjects. Laser Doppler readings did not change significantly as a result of the treatments. Therapy with iloprost produced a reduction in IL-1beta, L-selectin (CD 62 L) and IL-6. Conclusion: The change in immunological variables due to iloprost may explain the long-term effects of prostaglandins in the treatment of Raynaud’s phenomenon. From our results it is not possible to infer any preference for iloprost or alprostadil.

Acute and Chronic Changes in Platelet Volume and Count After Cardiopulmonary Bypass Induced Thrombocytopenia in Man

1987 ◽  
Vol 57 (01) ◽  
pp. 55-58 ◽  
Author(s):  
J F Martin ◽  
T D Daniel ◽  
E A Trowbridge
Keyword(s):  
Platelet Count ◽  
Mean Platelet Volume ◽  
Artery Bypass ◽  
Bypass Graft ◽  
Control Group ◽  
Artery Bypass Graft ◽  
Platelet Volume ◽  
Young Males ◽  
The Mean

SummaryPatients undergoing surgery for coronary artery bypass graft or heart valve replacement had their platelet count and mean volume measured pre-operatively, immediately post-operatively and serially for up to 48 days after the surgical procedure. The mean pre-operative platelet count of 1.95 ± 0.11 × 1011/1 (n = 26) fell significantly to 1.35 ± 0.09 × 1011/1 immediately post-operatively (p <0.001) (n = 22), without a significant alteration in the mean platelet volume. The average platelet count rose to a maximum of 5.07 ± 0.66 × 1011/1 between days 14 and 17 after surgery while the average mean platelet volume fell from preparative and post-operative values of 7.25 ± 0.14 and 7.20 ± 0.14 fl respectively to a minimum of 6.16 ± 0.16 fl by day 20. Seven patients were followed for 32 days or longer after the operation. By this time they had achieved steady state thrombopoiesis and their average platelet count was 2.44 ± 0.33 × 1011/1, significantly higher than the pre-operative value (p <0.05), while their average mean platelet volume was 6.63 ± 0.21 fl, significantly lower than before surgery (p <0.001). The pre-operative values for the platelet volume and counts of these patients were significantly different from a control group of 32 young males, while the chronic post-operative values were not. These long term changes in platelet volume and count may reflect changes in the thrombopoietic control system secondary to the corrective surgery.

Comparing the Genetic Detox Ability and Heavy Metal Burden in a Cohort of Samples of Egyptian Children and those with Autistic Spectrum Disorder

2019 ◽  
Author(s):  
Blaurock-Busch E
Keyword(s):  
Heavy Metal ◽  
Autism Spectrum ◽  
Control Group ◽  
Potentially Toxic Metals ◽  
Gstt1 Null Genotype ◽  
Egyptian Children ◽  
Glutathione S Transferases ◽  
Metal Burden ◽  
Detoxification Pathway

The heavy metal burden of patients with Autism spectrum disorders (ASD) has been widely discussed [1-5]. Present knowledge suggests that ASD patients, compared to ‘normal’s’ show a greater metal burden, which may be a cause of the ASD pathogenesis, possibly due to a limited detoxification potential. We thus aimed to evaluate if the metal burden of ASD children is due to comprised detoxification ability, and if missing of enzymes such as the glutathione-S-transferases provide an explanation, or if additional factors play a role. Genetically, we noticed a slight difference in the detoxification ability of the ASD group compared to the Control group. In the ASD group, carrier of the genotype GSTT1 null genotype (i.e. the homozygous loss) are 1.7 times more common as in the Control group and the GSTT1 allele is more frequent in the ASD patient collective. These findings are not statistically significant but indicate a trend. In addition, our data indicates that levels of potentially toxic metals in blood and hair of both groups demonstrate a similar immediate and long-term exposure. However, 36% of the ASD group showed signs of zinc deficiency compared to 11% of the Control group and this points towards inefficiency of the Phase I detoxification pathway. More research is needed to explore the role of other elements in the detoxification pathway.

Effectiveness of mobile applications on healthy lifestyles aimed at diabetic patients: review of systematic reviews. (Preprint)

2019 ◽  
Author(s):  
Francisco Jesús Represas Carrera Sr ◽  
Ángel Alfredo Martínez Ques Sr ◽  
Ana Clavería Fontán Sr
Keyword(s):  
Quality Of Life ◽  
Diabetes Mellitus ◽  
Systematic Reviews ◽  
Mobile Applications ◽  
Control Group ◽  
Diabetic Patients ◽  
Healthy Lifestyles ◽  
Major Public Health Problem

BACKGROUND Diabetes mellitus is currently a major public health problem worldwide. It is traditionally approached in a clinical inpatient relationship between the patient and the healthcare professional. However, the rise of new technologies, particularly mobile applications, is revolutionizing the traditional healthcare model through the introduction of telehealthcare. OBJECTIVE (1) To assess the effects of mobile applications for improving healthy lifestyles on the quality of life and metabolic control of diabetes mellitus in adult patients. (2) To describe the characteristics of the mobile applications used, identify the healthy lifestyles they target, and describe any adverse effects their use may have. METHODS Review of systematic reviews and meta-analysis, following the guidelines of the Cochrane Collaboration and the Joanna Briggs Institute. We included studies that used any mobile application aimed at helping patients improve self-management of diabetes mellitus by focusing on healthy lifestyles. Studies needed to include a control group receiving regular care without the use of mobile devices. In May 2018, a search was conducted in Medline, Embase, Cochrane, LILACS, PsychINFO, Cinahl and Science Direct, updated in May 2019. The methodological quality of the studies was assessed using the Amstar-2 tool. RESULTS Seven systematic reviews of 798 articles were initially selected for analysis. The interventions had a duration of between 1 and 12 months. Mobile applications focused singly or simultaneously on different lifestyles aspects (diet, physical exercise, motivation, blood glucose levels, etc.). There are significant changes in HbA1c values, body weight and BMI, although in others, such as lipid profile, quality of life, or blood pressure, there is no clear improvement. CONCLUSIONS There is clear evidence that the use of mobile applications improves glycemic control in diabetic patients in the short term. There is a lack of evidence in its long-term benefits. It is thus necessary to carry out further studies to learn about the long-term effectiveness of mobile applications aimed at promoting the healthy lifestyles of diabetic patients. CLINICALTRIAL PROSPERO Register: CRD42019133685

Long-Term Follow-Up of Early Cochlear Implant Device Activation

2021 ◽  
pp. 1-11
Author(s):  
Stefanie Bruschke ◽  
Uwe Baumann ◽  
Timo Stöver
Keyword(s):  
Speech Recognition ◽  
Side Effects ◽  
Cochlear Implant ◽  
Surgical Techniques ◽  
Control Group ◽  
First Year ◽  
Safe Procedure ◽  
Sound Processor

Background: The cochlear implant (CI) is a standard procedure for the treatment of patients with severe to profound hearing loss. In the past, a standard healing period of 3–6 weeks occurred after CI surgery before the sound processor was initially activated. Advancements of surgical techniques and instruments allow an earlier initial activation of the processor within 14 days after surgery. Objective: Evaluation of the early CI device activation after CI surgery within 14 days, comparison to the first activation after 4–6 weeks, and assessment of the feasibility and safety of the early fitting over a 12 month observation period were the objectives of this study. Method: In a prospective study, 127 patients scheduled for CI surgery were divided into early fitting group (EF, n = 67) and control group (CG, n = 60). Individual questionnaires were used to evaluate medical and technical outcomes of the EF. Medical side effects, speech recognition, and follow-up effort were compared with the CG within the first year after CI surgery. Results: The early fitting was feasible in 97% of the EF patients. In the EF, the processor was activated 25 days earlier than in the CG. No major complications were observed in either group. At the follow-up appointments, side effects such as pain and balance problems occurred with comparable frequency in both groups. At initial fitting, the EF showed a significantly higher incidence of medical minor complications (p < 0.05). When developing speech recognition within the first year of CI use, no difference was observed. Furthermore, the follow-up effort within the first year after CI surgery was comparable in both groups. Conclusions: Early fitting of the sound processor is a feasible and safe procedure with comparable follow-up effort. Although more early minor complications were observed in the EF, there were no long-term wound healing problems caused by the early fitting. Regular inspection of the magnet strength is recommended as part of the CI follow-up since postoperative wound swelling must be expected. The early fitting procedure enabled a clear reduction in the waiting time between CI surgery and initial sound processor activation.

scholarly journals Lichtenstein inguinal hernia repairs with porcine small intestine submucosa: a 5- year follow-up. a prospective randomized controlled study

2021 ◽  
Author(s):  
Baoshan Li ◽  
Xin Zhang ◽  
Yi Man ◽  
Jiadong Xie ◽  
Wei Hu ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Inguinal Hernia ◽  
Hernia Repair ◽  
Term Effect ◽  
Control Group ◽  
Small Intestine Submucosa ◽  
Long Term Effect ◽  
Porcine Small Intestine Submucosa

Abstract Porcine small intestine submucosa (SIS) biologic patch has been used in inguinal hernia repair. However, there are little data available to assess the long-term effect after repair. This study aimed to explore the long-term effect of SIS patch in open inguinal hernia repair. Sevent-six patients with unilateral inguinal hernia were treated with Lichtenstein tension-free hernia repair using SIS patch (Beijing Datsing Bio-Tech Co., Ltd.) and Surgisis patch (COOK, USA) in Tianjin Union Medical Center and China-Japan Friendship Hospital. In the trial, the long-term efficacy of the treatment group and the control group were compared. A total of 66 patients in both groups received long-term follow-up (&gt; 5 years) after surgery, with a follow-up rate of 86.8%. During the follow-up period, there was one case of recurrence, one case of chronic pain in the control group. There was no statistically significant difference (P &gt; 0.05) in terms of recurrence, chronic pain, foreign body sensation and infection between the two groups of patients. After long-term observations, it has been found that the porcine small intestinal submucosa (SIS) biological patch is safe and effective for inguinal hernia Lichtenstein repair, and has a low recurrence rate and complication rate.

scholarly journals Role and effectiveness of complex and supervised rehabilitation on overall and hand function in systemic sclerosis patients—one-year follow-up study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michał Waszczykowski ◽  
Bożena Dziankowska-Bartkowiak ◽  
Michał Podgórski ◽  
Jarosław Fabiś ◽  
Arleta Waszczykowska
Keyword(s):  
Systemic Sclerosis ◽  
Hand Function ◽  
Exercise Program ◽  
Rehabilitation Program ◽  
Long Term Results ◽  
Home Exercise ◽  
Control Group ◽  
Study Group

AbstractThe aim of this study was to estimate the long-term results of complex and supervised rehabilitation of the hands in systemic sclerosis (SSc) patients. Fifty-one patients were enrolled in this study: 27 patients (study group) were treated with a 4-week complex, supervised rehabilitation protocol. The control group of 24 patients was prescribed a home exercise program alone. Both groups were evaluated at baseline and after 1-, 3-, 6-, and 12-months of follow-up with the Disability of the Arm, Shoulder and Hand Questionnaire (DAHS) as the primary outcome, pain (VAS—visual analog scale), Cochin Hand Function Scale (CHFS), Health Assessment Questionnaire Disability Index (HAQ-DI), Scleroderma-HAQ (SHAQ), range of motion (d-FTP—delta finger to palm, Kapandji finger opposition test) and hand grip and pinch as the secondary outcomes. Only the study group showed significant improvements in the DASH, VAS, CHFS and SHAQ after 1, 3 and 6 months of follow-up (P = 0.0001). Additionally, moderate correlations between the DASH, CHFS and SHAQ (R = 0.7203; R = 0.6788; P = 0.0001) were found. Complex, supervised rehabilitation improves hand and overall function in SSc patients up to 6 months after the treatment but not in the long term. The regular repetition of this rehabilitation program should be recommended every 3–6 months to maintain better hand and overall function.

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