Transition from connected to fragmented vegetation across an environmental gradient: scaling laws in ecotone geometry

A change in the environmental conditions across space—for example, altitude or latitude—can cause significant changes in the density of a vegetation type and, consequently, in spatial connectivity. We use spatially explicit simulations to study the transition from connected to fragmented vegetation. A static (gradient percolation) model is compared to dynamic (gradient contact process) models. Connectivity is characterized from the perspective of various species that use this vegetation type for habitat and differ in dispersal or migration range, that is, “step length” across the landscape. The boundary of connected vegetation delineated by a particular step length is termed the “ hull edge.” We found that for every step length and for every gradient, the hull edge is a fractal with dimension 7/4. The result is the same for different spatial models, suggesting that there are universal laws in ecotone geometry. To demonstrate that the model is applicable to real data, a hull edge of fractal dimension 7/4 is shown on a satellite image of a piñon‐juniper woodland on a hillside. We propose to use the hull edge to define the boundary of a vegetation type unambiguously. This offers a new tool for detecting a shift of the boundary due to a climate change

Significance of groundwater discharge along the coast of Poland as a source of dissolved metals to the southern Baltic Sea

© The Author(s), 2016. This is the author's version of the work and is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Pollution Bulletin 109 (2016): 151–162, doi:10.1016/j.marpolbul.2016.06.008.Fluxes of dissolved trace metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn) via groundwater discharge along the southern Baltic Sea have been assessed for the first time. Dissolved metal concentrations in groundwater samples were less variable than in seawater and were generally one or two orders of magnitude higher: Cd (2.1-2.8 nmolL−1), Co (8.70-8.76 nmolL−1), Cr (18.1-18.5 nmolL−1), Mn (2.4-2.8 μmolL−1), Pb (1.2-1.5 nmolL−1), Zn (33.1-34.0 nmolL−1). Concentrations of Cu (0.5-0.8 nmolL−1) and Ni (4.9-5.8 nmolL−1) were, respectively, 32 and 4 times lower, than in seawater. Groundwater-derived trace metal fluxes constitute 93% for Cd, 80% for Co, 91% for Cr, 6% for Cu, 66% for Mn, 4% for Ni, 70% for Pb and 93% for Zn of the total freshwater trace metal flux to the Bay of Puck. Groundwater-seawater mixing, redox conditions and Mn-cycling are the main processes responsible for trace metal distribution in groundwater discharge sites.The study reports the results obtained within the framework of the following projects: the statutory activities of the Institute of Oceanology Polish Academy of Sciences theme 2.2, research project No. 2012/05/N/ST10/02761 sponsored by the National Science Centre, and AMBER, the BONUS+ EU FP6 Project. We would like to thank Polish-U.S. Fulbright Commission for funding Szymczycha B. post-doctoral studies at USGS.2017-06-1

Peningkatan Kemampuan Pemecahan Masalah Matematis Menggunakan Pendekatan Saintifik dan Pendekatan Ctl

This research aims to obtain information about the effect of instruction using scientific approach on the improvement of mathematical problem solving ability among students of State Junior High School (SMP Negeri) 13 Pontianak, West Kalimantan. The method used in this research was experiment research with a randomized pretest-posttest comparison group design. The results of data analysis showed that there were significant differences between the pretest and the posttest, namely using the scientific approach (pretest: 61.78%; posttest: 69.3 3%) and using CTL approach (pretest 58.50%; posttest 65.89%). This suggests that the improvement of the students\u27 ability in the mathematical problem solving using scientific approach is higher than the ability in the mathematical problem solving using contextual teaching and learning, and the improvement of the students\u27 ability is classified as moderate

Depth of the vadose zone controls aquifer biogeochemical conditions and extent of anthropogenic nitrogen removal

© The Author(s), 2017. This is the author's version of the work and is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Water Research 123 (2017): 794-801, doi:10.1016/j.watres.2017.06.048.We investigated biogeochemical conditions and watershed features controlling the extent of nitrate removal through microbial dinitrogen (N2) production within the surficial glacial aquifer located on the north and south shores of Long Island, NY, USA. The extent of N2 production differs within portions of the aquifer, with greatest N2 production observed at the south shore of Long Island where the vadose zone is thinnest, while limited N2 production occurred under the thick vadose zones on the north shore. In areas with a shallow water table and thin vadose zone, low oxygen concentrations and sufficient DOC concentrations are conducive to N2 production. Results support the hypothesis that in aquifers without a significant supply of sediment-bound reducing potential, vadose zone thickness exerts an important control of the extent of N2 production. Since quantification of excess N2 relies on knowledge of equilibrium N2 concentration at recharge, calculated based on temperature at recharge, we further identify several features, such as land use and cover, seasonality of recharge, and climate change that should be considered to refine estimation of recharge temperature, its deviation from mean annual air temperature, and resulting deviation from expected equilibrium gas concentrations.Project supported by the Polish-U.S. Fulbright Commission, the USGS Coastal and Marine Geology Program, the National Fish and Wildlife Foundation, and the USGS/National Park Service Water-Quality Assessment and Monitoring program.2019-06-1

Excitons in InGaAs Quantum Dots without Electron Wetting Layer States

The Stranski-Krastanov (SK) growth-mode facilitates the self-assembly of quantum dots (QDs) using lattice-mismatched semiconductors, for instance InAs and GaAs. SK QDs are defect-free and can be embedded in heterostructures and nano-engineered devices. InAs QDs are excellent photon emitters: QD-excitons, electron-hole bound pairs, are exploited as emitters of high quality single photons for quantum communication. One significant drawback of the SK-mode is the wetting layer (WL). The WL results in a continuum rather close in energy to the QD-confined-states. The WL-states lead to unwanted scattering and dephasing processes of QD-excitons. Here, we report that a slight modification to the SK-growth-protocol of InAs on GaAs -- we add a monolayer of AlAs following InAs QD formation -- results in a radical change to the QD-excitons. Extensive characterisation demonstrates that this additional layer eliminates the WL-continuum for electrons enabling the creation of highly charged excitons where up to six electrons occupy the same QD. Single QDs grown with this protocol exhibit optical linewidths matching those of the very best SK QDs making them an attractive alternative to standard InGaAs QDs

Quantitative Analysis of Proteome Dynamics in Chinese Hamster Ovary cells

The overall goal of this research was to better understand the mechanisms underlying the physiology of CHO cells, the most important mammalian host for recombinant protein production. The publication of complete genome of CHO cells allowed the use of mass-spectrometry based proteomic tools to study protein expression. Among several different sample preparation methods for mass spectrometry, in-gel trypsin digest and FASP were found to be the most robust and optimal for high-coverage CHO proteome analysis. Global changes in protein expression between exponential and stationary phases were determined using SILAC for parental GS K-O and producing E22 cell lines. >4000 proteins have been quantified and more than 100 proteins have been statistically differentiated. Proteins up-regulated in exponential phase control cell cycle and DNA replication, while proteins up-regulated in the stationary phase are involved in stress response and signalling, making them interesting targets for cellular engineering. In addition to quantifying relative changes in protein expression between two phases of cell culture, more than 4000 protein copy numbers were calculated for parental and producing cell lines using TPA method. Protein turnover, described as the balance between protein synthesis and degradation, was calculated for >3000 cellular proteins. Combining these two parameters together allowed determination of top 10 proteins corresponding to 20% of global turnover rate. Production of monoclonal antibody was top priority, causing metabolic burden on cells. KEGG and GO annotation suggests that 600 up-regulated proteins in E22 producing cell line explained their clonal selection based on highest growth and productivity. Interestingly, there was no major differences found between amino acid and codon usage between parental and producing cell lines. In summary, a large-scale proteomic data set containing qualitative, quantitative and dynamic information on protein expression for industrially relevant CHO cell lines

Tuberculosis Screening and Treatment of Latent Tuberculosis Infection among International College Students

Tuberculosis (TB) remains in the crosshairs of many public health policies worldwide that are taking aim at eradicating this potentially curable and preventable illness. Although tuberculosis (TB) incidence has been declining in the United States for over a decade, it still remains a serious public health concern. Currently, there is no public health policy that requires the screening of non-immigrant international university students visiting the United States. Given the rising numbers of visiting international students, this population has come under scrutiny as potential vectors of transmission of TB into the United States. Foreign-born persons from countries with consistently elevated TB prevalence rates constitute an important high risk group for both TB exposure and infection in this setting. Although some universities have their own public health protocols, not all universities have a policy of screening international, non-immigrant students for TB. To further investigate the situation, we reviewed the medical charts of international students visiting the University of Florida. Students who visited the health department for evaluation of TB skin tests from January1998 to February 2002 were studied. Of the students with a positive tuberculin test (skin test \u3e10mm induration), 97.6% had normal chest radiographs. Only 31 students (10.8%) agreed to undergo treatment for latent TB infection (LTBI), of which only half completed a six to nine month course and 86.8% were lost to follow-up. To attempt complete eradication of TB from the United States, universities with at-risk populations should consider the implementation of strict guidelines and well defined policies for the screening, follow-up and treatment of active and latent TB in international students

Investigation of the epitaxial growth of AIIIBV-N heterostructures for solar cell applications

The InGaAsN/GaAs heterostructures proposed in 1996 by Kondow et al. have been successfully used in telecom laser constructions on GaAs substrate. Additionally, the InGaAsN with a bandgap of 1 eV are lattice matched to both GaAs and Ge for the nitrogen and indium contents of around 3 % and 9 %, respectively. These features make this semiconductor an ideal candidate for high-efficiency multijunction solar cells (MJSCs) based on the Ge/InGaAsN/GaAs/InGaP structure. The growth technology of the GaAsN alloy-based diluted nitrides is very difficult because of the large miscibility gap between GaAs and GaN. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2097

Neurofeedback training for peak performance

Aim. One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions. The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in spontaneous EEG and event related potentials (ERPs). Case study. The case is presented of an Olympic athlete who has lost his performance confidence after injury in sport. He wanted to resume his activities by means of neurofeedback training. His QEEG/ERP parameters were assessed before and after 4 intensive sessions of neurotherapy. Dramatic and statistically significant changes that could not be explained by error measurement were observed in the patient. Conclusion. Neurofeedback training in the subject under study increased the amplitude of the monitoring component of ERPs generated in the anterior cingulate cortex, accompanied by an increase in beta activity over the medial prefrontal cortex. Taking these changes together, it can be concluded that that even a few sessions of neurofeedback in a high performance brain can significantly activate the prefrontal cortical areas associated with increasing confidence in sport performance