Meningkatkan Hasil Belajar Siswa Pada Mata Pelajaran Sains Melalui Penggunaan Alat Peraga Di Kelas V SDN 1 Dolong A

Penelitian ini merupakan penelitian tindakan kelas. Penelitian ini dilakukan dalam dua siklus dengan tujuan meningkatkan hasil belajar siswa dengan menggunakan alat peraga di kelas V SDN 1 Dolong A. Subyek penelitian ini adalah siswa kelas V SDN 1 Dolong A yang berjumlah 32 orang terdiri dari 15 orang laki-laki dan 17 orang perempuan. Hasil penelitian pada siklus I menunjukkan rata-rata hasil observasi aktivitas siswa diperoleh persentase 71,87% dengan kategori baik, persentase aktivitas guru 77% kategori baik, persentase daya serap klasikal 56,63% dan tuntas klasikal sebesar 71,87%. Pada siklus II diperoleh rata-rata persentase aktivitas siswa sebesar 87,5% dengan kategori sangat baik, persentase aktivitas guru 90,38% kategori sangat baik, persentase daya serap klasikal 80% dan persentase tuntas klasikal sebesar 85%. Hal ini telah memenuhi indikator keberhasilan yang telah ditetapkan dengan nilai rata-rata hasil belajar minimal 70 dan ketuntasan klasikal sudah mencapai indikator keberhasilan minimal 80%

DETECTION OF THE INFLUENCE OF TRANSCRANIAL ELECTROSTIMULATION ON THE STESS RESISTANCE OF STUDENTS BY THE TEST OF T. HOLMES AND R. RAHE

Aim. The study was designed to establish the influence of transcranial electrostimulation on the stress tolerance of students by the method of T. Holmes and R. Rahe.Materials and methods.The observations were made on 127 students aged 19-22. They were 50 boys and 77 girls. The students were divided into the main group (78 people) and the comparison group (49 people). Transcranial electrostimulation was carried out for the students of the main group: 2 sessions per week and 5 sessions per week. Stress resistance was assessed by the test of stress resistance and social adaptation of T. Holmes and R. Rahe before the course of transcranial electrostimulation and after it. The level of stress resistance was determined in the comparison group within the same time frame. Transcranial electrostimulation (TES) was performed by the “Transair-03” apparatus on the testees in the sitting position. The value of the pulse current of 3 mA, frequency 7.5 Hz was used. The exposure time was 30 minutes. The results of the study were processed with the help of the “Statistika 6.0” computer program. Results. At the end of the school year, students had low, threshold and high levels of stress resistance. These levels of resistance to stress remained in those individuals who did not undergo transcranial electrostimulation, and also in students who had 2 transcranial electrostimulation sessions per week. After 5 sessions of transcranial electrostimulation per week, students had a threshold and high levels of stress resistance; there was no low level. After 5 sessions of transcranial electrostimulation the total number of points in students with a threshold level of stress resistance statistically decreased by 11,0% in comparison with the initial result. The total number of points after transcranial electrostimulation in students with a high level of stress resistance statistically decreased by 8,4%. Conclusion. The results indicate an increase in the level of students' stress tolerance and the effectiveness of transcranial therapy for at least 5 sessions per week

Influence of TES-therapy on the character of stress-induced expression of C-FOS in the paraventricular nucleus of the hypothalamus

In this study, the ability of transcranial electrostimulation (TES-therapy) to inhibit the hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis (reflected in the change in the character of c-fcs expression by neurons in the paraventricular nucleus of the hypothalamus) under conditions of combined stress and orthostatic test was evaluated. The experimental animals were divided into two groups: subjected to stress (comparison group, n = 20) and subjected to stress under TES-therapy (main group, n = 20). The results of the study indicate that TES-therapy favorably affects the psychophysical characteristics of rats and negatively modulates the function of the HPA axis, which allows us to conclude that this technique is an effective approach to the treatment of stress-related disorders.В настоящем исследовании оценивалась способность транскраниальной электростимуляции (ТЭС-терапии) предотвращатъ гиперактивацию гипоталамо-гипофизарно-надпочечниковой (ГГН) оси (отражающуюся в изменении характера экспрессии c-fos нейронами паравентрикулярного ядра гипоталамуса) в условиях комбинированного стресса, в качестве модели которого использовались тест вынужденного плавания и ортостатический тест. С этой целью экспериментальные животные были разделены на две группы: подвергавшиеся стрессу (группа сравнения, п=20) и повергавшиеся стрессу и получавшие ТЭС-терапию (основная группа, п=20). Результаты исследования указывают на то, что ТЭС-терапия благоприятно воздействует на психофизические показатели крыс и отрицательно модулирует функцию ГГН оси. Это позволяет заключить, что данная методика является эффективным подходом к лечению ассоциированных со стрессом расстройств

The Alaska Arctic Vegetation Archive (AVA-AK)

The Alaska Arctic Vegetation Archive (AVA-AK, GIVD-ID: NA-US-014) is a free, publically available database archive of vegetation-plot data from the Arctic tundra region of northern Alaska. The archive currently contains 24 datasets with 3,026 non-overlapping plots. Of these, 74% have geolocation data with 25-m or better precision. Species cover data and header data are stored in a Turboveg database. A standardized Pan Arctic Species List provides a consistent nomenclature for vascular plants, bryophytes, and lichens in the archive. A web-based online Alaska Arctic Geoecological Atlas (AGA-AK) allows viewing and downloading the species data in a variety of formats, and provides access to a wide variety of ancillary data. We conducted a preliminary cluster analysis of the first 16 datasets (1,613 plots) to examine how the spectrum of derived clusters is related to the suite of datasets, habitat types, and environmental gradients. We present the contents of the archive, assess its strengths and weaknesses, and provide three supplementary files that include the data dictionary, a list of habitat types, an overview of the datasets, and details of the cluster analysis

Механизмы ангиогенеза при трансплантации тканеинженерных конструкций

There is a number of problems regarding bioengineered structures creation that require further study in the fi eld of regenerative medicine. One of the critical tasks that require solution is the fact that tissue engineered constructions, as a rule, are large, which signifi cantly limits the possibility of diffusion of nutrients and oxygen in them. Thus, the key task of fundamental medicine is to fi nd a technology for restoring the perfusion of the structures created. The article presents a modern overview of the mechanisms of angiogenesis and possible ways of its stimulation during transplantation of tissue engineered constructions.В области регенеративной медицины при создании биоинженерных конструкций имеется ряд проблем, нуждающихся в дальнейшем изучении. Одной из актуальных задач, требующих решения, является тот факт, что тканеинженерные конструкции, как правило, имеют большие размеры, что значительно ограничивает возможность диффузии в них питательных веществ и кислорода. Таким образом, ключевая задача фундаментальной медицины заключается в поиске технологии восстановления перфузии создаваемых конструкций. В статье представлен современный обзор механизмов ангиогенеза и возможных путей его стимуляции при трансплантации тканеинженерных конструкций

The Alaska Arctic Vegetation Archive (AVA-AK)

The Alaska Arctic Vegetation Archive (AVA-AK, GIVD-ID: NA-US-014) is a free, publically available database archive of vegetation-plot data from the Arctic tundra region of northern Alaska. The archive currently contains 24 datasets with 3,026 non-overlapping plots. Of these, 74% have geolocation data with 25-m or better precision. Species cover data and header data are stored in a Turboveg database. A standardized Pan Arctic Species List provides a consistent nomenclature for vascular plants, bryophytes, and lichens in the archive. A web-based online Alaska Arctic Geoecological Atlas (AGA-AK) allows viewing and downloading the species data in a variety of formats, and provides access to a wide variety of ancillary data. We conducted a preliminary cluster analysis of the first 16 datasets (1,613 plots) to examine how the spectrum of derived clusters is related to the suite of datasets, habitat types, and environmental gradients. Here, we present the contents of the archive, assess its strengths and weaknesses, and provide three supplementary files that include the data dictionary, a list of habitat types, an overview of the datasets, and details of the cluster analysis

Vegetation Type Dominates the Spatial Variability in CH<inf>4</inf> Emissions Across Multiple Arctic Tundra Landscapes

Methane (CH4) emissions from Arctic tundra are an important feedback to global climate. Currently, modelling and predicting CH4 fluxes at broader scales are limited by the challenge of upscaling plot-scale measurements in spatially heterogeneous landscapes, and by uncertainties regarding key controls of CH4 emissions. In this study, CH4 and CO2 fluxes were measured together with a range of environmental variables and detailed vegetation analysis at four sites spanning 300 km latitude from Barrow to Ivotuk (Alaska). We used multiple regression modelling to identify drivers of CH4 flux, and to examine relationships between gross primary productivity (GPP), dissolved organic carbon (DOC) and CH4 fluxes. We found that a highly simplified vegetation classification consisting of just three vegetation types (wet sedge, tussock sedge and other) explained 54% of the variation in CH4 fluxes across the entire transect, performing almost as well as a more complex model including water table, sedge height and soil moisture (explaining 58% of the variation in CH4 fluxes). Substantial CH4 emissions were recorded from tussock sedges in locations even when the water table was lower than 40 cm below the surface, demonstrating the importance of plant-mediated transport. We also found no relationship between instantaneous GPP and CH4 fluxes, suggesting that models should be cautious in assuming a direct relationship between primary production and CH4 emissions. Our findings demonstrate the importance of vegetation as an integrator of processes controlling CH4 emissions in Arctic ecosystems, and provide a simplified framework for upscaling plot scale CH4 flux measurements from Arctic ecosystems