Keanekaragaman Jenis dan Kepadatan Zooplankton di Perairan Pulau Makassar Kota Baubau

The purpose of the study was to determine the type and amount of zooplankton in the waters of Makassar Island, Baubau City. From the results of this study, it is expected that significant information regarding the types and zooplankton found in the sea around Makassar Island, Baubau City, whose waters are suitable for aquaculture. Furthermore, it is hoped that the results of this study can help improve and optimize the use of aquatic biological resources in the future. This research was conducted in the waters of Makassar Island, Baubau City, from August to October 2021. Sample identification was carried out at the Biology Laboratory of the Muhammadiyah University of Buton. The tool in this research field is plankton net no. 25 to filter zooplankton, GPS determines the sampling location, thermometer measures temperature, handrefactometer measures salinity, DO (Dissolved Oxygen) meter measures sea air oxygen, plastic bottles store seawater samples, small plastic bottles store zooplankton samples, and cool boxes for storing samples. Materials in the field are label paper and markers to label the sample, 70% alcohol to preserve the sample, and aqua water to sterilize the instrument. 1) From the three highest locations found 18 genera of zooplankton belonging to the Crustacea group. 2) With 33 ind/l, the genus OIthona dominates the waters of Makasar Island, Baubau City. 3) In the three locations, there was no variation in zooplankton density.

The use of mulching material in the cultivation of apple and pear in a small plastic greenhouses

This article presents the results of studies that were conducted in a small-sized film greenhouse for growing аpple and pear seedlings according to different planting schemes with mulching between rows with black span bond and matting. It was found that mulching between rows creates more favorable conditions for growing plants. The temperature regime of the soil improves, especially at the depth of the root layer. The row spacing soil is less compacted, since multiple loosening and weeding are not required. The mulching materials used freely pass water and mineral elements dissolved in it. Black woven matting is recognized as the best material for mulching between rows of apple and pear trees in a small film greenhouse. The applied schemes of planting winter grafts of apple and pear trees and mulching of row spacing made it possible to completely abandon the use of intensive manual labor on weeding and loosening the soil. Using three-line planting instead of one-line planting allows to significantly increase the yield of planting material per unit area.

SMALL EFFORT, BIG RESULTS: THROWING AND CATCHING ACTIVITIES USING PLASTIC BALL TO FOSTER CHILD'S KINESTHETIC ABILITY

The purpose of this study was to improve the kinesthetic ability of group A, Ria Pembangunan Kindergarten, Sentani, Jayapura through a throwing-catching game using the small plastic ball. This research uses the action research method. Participants were collected using purposive sampling by involving 12 children in group A. Kinesthetic ability is one aspect that plays an essential role in child development. In the first cycle, the results showed that the child's kinesthetic ability reached 49.30%, including throwing with one hand over the shoulder, reaching 45.83%, throwing with one hand below 52.08%, and catching the ball 50%. As for the second cycle, it increased to 82.64%, including throwing with one hand over the shoulder, reaching 81.22%, throwing with one hand below, reaching 85.42%, and the aspect of catching the ball reaches 83.33%. Thus, the results showed that throwing-catching games using small plastic balls could improve the kinesthetic ability of group A at Ria Pembangunan Sentani Kindergarten, Jayapura Regency, Papua.

Designing a new type of drive unit for the analysis of small plastic gears

When testing small plastic gears, the accuracy is always a problem. These gears are typically designed to perform their function with certainty, while other operating factors, such as noise, efficiency, and the similar factors play a marginal role in design or are not even considered (VDI 2731, 2009). However, when designing such gears, the designer is forced to face the limitations of known and recognized standards, guidelines, and methods, as well as the special characteristics of the installation environment. The problems arising from these can be explored mainly through experiments. Experiments with gears can be costly in this case because they often require at least two orders of magnitude more accurate measuring instruments than we have been accustomed to with normal-sized gears, and obviously appropriate equipment is required. In many cases, the use of drive units described in this article is a good solution to the problem of costly equipment. These drive units can contain gears of a given wheelbase, and their output and input shafts have the same external dimensions. This simplifies the problems of the equipment and makes the effects of the errors well comparable. This article describes the purposes and how we have used this type of drive units at the Institute of Machine and Product Design so far, what limitations they have, and what solutions can be used to develop these drive units to be able to perform more accurate tests.

Organ-on-Chip: Playing LEGO® With Mini-Organs to Reduce Animal Testing and Make Medicines Safer

Have you ever pictured yourself as a LEGO®-mini-figure? That is pretty cool, right?! But now, instead of picturing yourself as an astronaut, superhero, or elf-figure, try to imagine your own body being miniature and built from LEGO®–one brick for each of your organs. Sound weird? Let us explain why a mini LEGO®-version of you could be extremely useful and could become reality in the future. Such technology might help end testing that uses laboratory animals and help your doctors understand your disease. We use people’s cells and small plastic housings to build mini-organs the size of small LEGO®-bricks, such as a beating heart or energy-storing fat tissue. Similar to playing LEGO®, we can also connect different organ-bricks and study how they talk and work with each other. In this article, we will tell you how this all works and why it is so much better than animal experiments.

Plastic contamination of soil: is compost the source?

<p>Plastic contamination is a major environmental topic, however, only little knowledge exists about plastic contamination of agroecosystems. Especially the prevalence of plastic in soil and potential entry paths remain largely unknown. Consequently, this study aims at evaluating to what degree compost application is a source of plastic for soil. To do so, we analyzed plastic in 8 different municipal and commercial composts and in topsoil (0-30 cm) of a 12-year compost fertilizer trial with 0, 5, 10 and 20 t compost per hectare. After method testing and adjustment (yielding 76-100% recovery of spiked plastic particles), plastic was analyzed via density separation (ZnCl<sub>2</sub>) and light microscopy. We found 12±8 to 46±8 plastic items kg<sup>-1</sup> compost; concentrations of plastic items > 5 mm were highly variable and ranged between 0.04±0.08 to 1.35±0.53 g kg<sup>-1 </sup>compost. In contrast to sewage sludge, which contains mostly fibers, in compost particles were dominant. In soil we found 0 to 66±8.5 plastic items kg<sup>-1 </sup>soil, with highest plastic concentrations in variants with highest compost application, i.e. soils with compost application had 2 to 2.5 higher plastic concentrations than control variants. However, we also could detect additional plastic sources as fields on the border of the trial (near a road) had 3 times higher plastic concentrations than inner fields, leading to a plastic contamination of up to 23 items kg<sup>-1</sup>. Consequently, we could confirm compost application as an entry path for plastic into soil, leading to a twofold increased plastic contamination of agricultural soil. The determined plastic input via compost might be a minimum estimate since small plastic items like nanoplastics were not included, which warrants further attention.  </p>