Dynamics of nutrient cycling on postharvested white spruce sites in interior Alaska

Thesis (Ph.D.) University of Alaska Fairbanks, 1990Various field and laboratory methods were used to characterize nutrient cycling on two mature white spruce sites, one recently harvested site and three 14-year-old harvested white spruce sites colonized by different plant communities and presenting different intensity of soil disturbance. Study sites were chosen on upland south facing sites and presented conditions of reduced environmental variability. Soil analysis showed no changes in pools of soil nutrient unless the forest floor was removed. On the other hand, some differences in the dynamics of nutrients were seen: (1) sites where the forest floor was removed showed low N mineralization rates; (2) N mineralization rates appeared faster in the surface soil of the recently harvested site than in mature white spruce sites; (3) the surface soil of sites regenerating to aspen showed the highest N mineralization rates of all 14-year-old sites. Field soil temperature, and field soil moisture content as well as N and lignin concentrations of the forest floor could not explain the differences in N mineralization rates between sites. This suggests that species colonization may influence N dynamics and that N cycling rate on regenerating sites is controlled by a small pool of rapidly cycling N. The determination of nutrient uptake and return by vegetation growing in the field indicated that nutrient cycling was much faster in 14-year-old aspen stands than on any other regenerating or mature site. The measurement of element availability with ion exchange resin bags indicated an increased leaching of nitrate, phosphate and sulfate at springtime, the second summer following harvesting. Poor correlations were obtained between conventional soil testing and ion exchange resin bag determinations. Comparisons between field and laboratory nutrient availability indices indicated that sites colonized by sprouting aspen exhibited the highest N cycling rates seen in this study. This observation makes aspen an interesting species to consider for mixed species management strategies

How Best Should We Manage Hybrid Poplar Plantations? Interactions of Site Preparation, Vegetation Control and Fertilization

The silviculture of hybrid poplars is a promising solution to reduce the pressure on natural forests while maintaining the wood supply to industries. However, hybrid poplars are sensitive to competing vegetation and to inadequate soil conditions and fertility. Possible management tools include mechanical site preparation (MSP), vegetation control, and fertilization. We present here the results after five years of growth for eight formerly forested sites (40 hectares total) on Podzols in the province of Quebec, Canada. The experimental design combines four MSP treatments (harrowing, scarifying, mounding, and no preparation) with four frequencies of plant competition control by brushing (from never to once a year) and N or N+P fertilization. The best growth was found in the following MSP treatments: mounding \u3e harrowing \u3e scarifying \u3e none. The effect of competition control is more evident on the more productive sites and in the less severe preparation treatments, which brings insight into the Grime-Tilman debate over the importance and intensity of competition. Fertilization can provide substantial improvement in immediate growth, although it does not seem to compensate for deficient root systems. We will discuss the causes and implications of our results for future management strategies of hybrid poplar plantations

Assessment of Prescribed Burning Effects in Paludified Black Spruce Forests in Ontario’s Clay Belt Region

Paludification, the accumulation of poorly decomposed organic matter principally originating from Sphagnum, transforms black spruce forests to forested peatlands in the prolonged absence of fire. High-severity wildfires reverse this process by burning the organic matter layer and thus restart forest succession; in contrast low severity wildfires remove only the tree layer and do not reduce paludification. On the Ontario Clay Belt, a physiogeographic region prone to paludification due to its cold climate and poor drainage, current forest harvest practices (Careful Logging Around Advanced Growth; CLAAG) mimic low severity fires by removing trees but lacking forest floor and soil disturbances caused by fire. Historically, prescribed burning after clear cut (PB) was used as a site preparation technique, and may also be used for controlling paludification as it burns part of the organic soil layer and enhances soil fertility by releasing nutrients. Our retrospective study examines three hypotheses; compared to CLAAG and clear cut, 1) PB has positive effects on soil conditions, 2) controls sphagnum colonisation and 3) results in better growth of black spruce. We sampled 24 sites, using ecological forest classification and harvest records to ensure site equivalency. Results show a significant positive effect of PB on soil decomposition, nutrient contents and pH values. PB reduces Sphagnum establishment and growth. PB significantly increases black spruce growth (terminal shoots), however no difference in mean tree height is observed among treatments. We put forth that these contradictory results could be explained by a time lag in natural regeneration after PB as suggested by forest vertical structure. While not a high severity fire, prescribed burning after clear cut in paludified stands on the Ontario Clay Belt emulates some of its effects. Therefore we conclude that unlike CLAAG, prescribed burning after clear cut facilitates the development of unpaludified stands in a managed landscape

Clinical Validation of Fragile X Syndrome Screening by DNA Methylation Array

Fragile X syndrome (FXS) is the most common inherited cause of intellectual disability. It is most frequently caused by an abnormal expansion of the CGG trinucleotide repeat (\u3e200 repeats) located in the promoter of the fragile X mental retardation gene (FMR1), resulting in promoter DNA hypermethylation and gene silencing. Current clinical tests for FXS are technically challenging and labor intensive, and may involve use of hazardous chemicals or radioisotopes. We clinically validated the Illumina Infinium HumanMethylation450 DNA methylation array for FXS screening. We assessed genome-wide and FMR1-specific DNA methylation in 32 males previously diagnosed with FXS, including nine with mosaicism, as well as five females with full mutation, and premutation carrier males (n = 11) and females (n = 11), who were compared to 300 normal control DNA samples. Our findings demonstrate 100% sensitivity and specificity for detection of FXS in male patients, as well as the ability to differentiate patients with mosaic methylation defects. Full mutation and premutation carrier females did not show FMR1 methylation changes. We have clinically validated this genome-wide DNA methylation assay as a cost- and labor-effective alternative for sensitive and specific screening for FXS, while ruling out the most common differential diagnoses of FXS, Prader-Willi syndrome, and Sotos syndrome in the same assay

Long-range electronic reconstruction to a dxz,yz-dominated Fermi surface below the LaAlO3/SrTiO3 interface

Low dimensionality, broken symmetry and easily-modulated carrier concentrations provoke novel electronic phase emergence at oxide interfaces. However, the spatial extent of such reconstructions - i.e. the interfacial ‘‘depth’’ - remains unclear. Examining LaAlO3/SrTiO3 heterostructures at previously unexplored carrier densities n2D 14 cm-2 , we observe a Shubnikov-de Haas effect for small in-plane fields, characteristic of an anisotropic 3D Fermi surface with preferential dxz,yz orbital occupancy extending over at least 100 nm perpendicular to the interface. Quantum oscillations from the 3D Fermi surface of bulk doped SrTiO3 emerge simultaneously at higher n2D. We distinguish three areas in doped perovskite heterostructures: narrow (nm) 2D interfaces housing superconductivity and/or other emergent phases, electronically isotropic regions far (\u3e120 nm) from the interface and new intermediate zones where interfacial proximity renormalises the electronic structure relative to the bulk

Natural plant diet impacts phenotypic expression of pyrethroid resistance in Anopheles mosquitoes

Success in reducing malaria transmission through vector control is threatened by insecticide resistance in mosquitoes. Although the proximal molecular mechanisms and genetic determinants involved are well documented, little is known about the influence of the environment on mosquito resistance to insecticides. The aim of this study was to assess the effect of plant sugar feeding on the response of Anopheles gambiae sensu lato to insecticides. Adults were fed with one of four treatments, namely a 5% glucose control solution, nectariferous flowers of Barleria lupulina, of Cascabela thevetia and a combination of both B. lupulina+C. thevetia. WHO tube tests were performed with 0.05% and 0.5% deltamethrin, and knockdown rate (KD) and the 24 h mosquito mortality were measured. Plant diet significantly influenced mosquito KD rate at both concentrations of deltamethrin. Following exposure to 0.05% deltamethrin, the B. lupulina diet induced a 2.5 fold-increase in mosquito mortality compared to 5% glucose. Species molecular identification confirmed the predominance of An. gambiae (60% of the samples) over An. coluzzii and An. arabiensis in our study area. The kdr mutation L1014F displayed an allelic frequency of 0.75 and was positively associated with increased phenotypic resistance to deltamethrin. Plant diet, particularly B. lupulina, increased the susceptibility of mosquitoes to insecticides. The finding that B. lupulina-fed control individuals (i.e. not exposed to deltamethrin) also displayed increased 24 h mortality suggests that plant-mediated effects may be driven by a direct effect of plant diet on mosquito survival rather than indirect effects through interference with insecticide-resistance mechanisms. Thus, some plant species may weaken mosquitoes, making them less vigorous and more vulnerable to the insecticide. There is a need for further investigation, using a wider range of plant species and insecticides, in combination with other relevant environmental factors, to better understand the expression and evolution of insecticide resistance

Identification of Epigenetic Signature Associated With Alpha Thalassemia/Mental Retardation X-linked Syndrome

BACKGROUND: Alpha thalassemia/mental retardation X-linked syndrome (ATR-X) is caused by a mutation at the chromatin regulator gene RESULTS: We performed genome-wide DNA methylation assessment of the peripheral blood samples from 18 patients with ATR-X and compared it to 210 controls. We demonstrated the evidence of a unique and highly specific DNA methylation epi-signature in the peripheral blood of ATRX patients, which was corroborated by targeted bisulfite sequencing experiments. Although genomically represented, differentially methylated regions showed evidence of preferential clustering in pericentromeric and telometric chromosomal regions, areas where ATRX has multiple functions related to maintenance of heterochromatin and genomic integrity. CONCLUSION: Most significant methylation changes in the 14 genomic loci provide a unique epigenetic signature for this syndrome that may be used as a highly sensitive and specific diagnostic biomarker to support the diagnosis of ATR-X, particularly in patients with phenotypic complexity and in patients wit

PENANAMAN NILAI-NILAI ANTI KORUPSI MELALUI KEGIATAN PEMBELAJARAN OUTING CLASS PENDIDIKAN KEWARGANEGARAAN (STUDI PADA SEKOLAH MENENGAH ATAS MUHAMMADIYAH 1 KARANGANYAR

ABSTRAK Atin Putri Sanyoto. K6411014. PENANAMAN NILAI - NILAI ANTI KORUPSI MELALUI KEGIATAN PEMBELAJARAN OUTING CLASS PENDIDIKAN KEWARGANEGARAAN (STUDI PADA SEKOLAH MENENGAH ATAS MUHAMMADIYAH 1 KARANGANYAR), Skripsi, Fakultas Keguruan dan Ilmu Pendidikan Universitas Sebelas Maret Surakarta. Juni, 2018. Tujuan penelitian ini adalah (1) mengetahui penanaman nilai-nilai anti korupsi melalui kegiatan pembelajaran outing class PKn pada peserta didik SMA Muhammadiyah 1 Karanganyar; (2) mengetahui dampak dari penanaman nilai-nilai anti korupsi melalui kegiatan pembelajaran outing class PKn terhadap karakter peserta didik SMA Muhammadiyah 1 Karanganyar. (3) mengetahui faktor-faktor pendukung dan penghambat penanaman nilai-nilai anti korupsi melalui kegiatan pembelajaran outing class PKn pada peserta didik SMA Muhammadiyah 1 Karanganyar; Penelitian ini merupakan penelitian kualitatif, Lokasi penelitian berada di SMA Muhammadiyah 1 Karanganyar. Sumber data berasal dari guru PKn dan peserta didik. Teknik pengumpulan data dengan observasi, wawancara dan analisis dokumen. Validitas data yang digunakan adalah triangulasi data. Analisis data yang digunakan adalah analisis data interaktif. Hasil penelitian menunjukan bahwa (1) Penanaman nilai-nilai anti korupsi di SMA Muhammadiyah 1 Karanganyar dilakukan melalui serangkaian kegiatan pembelajaran outing class PKn yang meliputi, a) Pra Kegiatan meliputi perencanaan acara dengan penunjukan dan pembagian peserta didik secara menyeluruh agar semuanya dapat berpartisipasi aktif; b) Seminar Sosialisasi Anti Korupsi; c) Simulasi Sidang Tindak Pidana Korupsi; e) Deklarasi Anti Korupsi; e) Lomba Baca Puisi Anti Korupsi; f) Lomba Dai Anti Korupsi; g) Lomba Majalah Dinding Anti Korupsi; h) Lomba Band Anti Korupsi; i) Pemakaian Pin Anti Korupsi; j) Kantin Kejujuran; (2) Dampak penanaman nilai-nilai anti korupsi terhadap karakter peserta didik yaitu, berhasil pada pengetahuan moral dengan bertambahnya pengetahuan mengenai tindakan korupsi dan nilai-nilai anti korupsi, serta pada perasaan moral dengan adanya rasa tidak suka terhadap tindakan korupsi, tapi belum pada tindakan moral, ada keinginan memiliki sikap anti korupsi akan tetapi tidak diiringi dengan pembiasaan sehingga belum tercipta karakter anti korupsi secara menyeluruh; (3) Faktor pendukung dan penghambat penanaman nilai-nilai anti korupsi meliputi, a) Faktor pendukung yaitu, keteladanan guru dengan memberikan contoh kepada siswa-siswanya sebagai role model dengan penghargaan guru yang terdisiplin serta kreativitas guru sebagai pendorong terciptanya gagasan untuk mengadakan kegiatan pembelajaran outing class PKn dengan menanamkan sembilan nilai integritas anti korupsi; b) Faktor penghambat meliputi terbatasnya sumber dana, kebiasaan individu yang masih koruptif, dan lingkungan masyarakat yang masih ditemukan ketidaktransparanan dan pungli. Kata kunci : penanaman nilai-nilai anti korupsi, pembelajaran outing clas