Toksisitas Bahan Pengawet Boron-kromium Terhadap Serangga Dan Jamur Pelapuk Kayu

Penelitian ini bertujuan untuk menguji toksisitas bahan pengawet boron-kromium terhadap rayap dan jamur pelapuk kayu. Bahan yang digunakan merupakan bahan kimia dengan kualitas teknis. Pengawetan contoh uji dilakukan menggunakan proses vakum tekan dengan lima konsentrasi yang berbeda. Untuk pengujian terhadap rayap tanah, 200 ekor pekerja rayap tanah Coptotermes curvignathus Holmgren dimasukkan ke dalam jam pot yang berisi media pasir dan contoh uji berupa kayu yang berukuran 25 mm x 25 mm x 5 mm. Untuk rayap kayu kering, lima puluh ekor pekerja rayap kayu kering Cryptotermes cynocephalus Light dimasukkan ke dalam tabung gelas berdiameter 18 mm dengan tinggi 35 mm yang dipasang pada salah satu sisi terlebar contoh uji yang berukuran 50 mm x 25 mm x 20 mm. Sementara terhadap jamur pelapuk kayu, pengujian dilakukan dengan jamur Schizophyllum commune yang dibiakkan dalam mediapotato dextrose agar (PDA). Hasil pengujian menunjukkan bahwa bahan pengawet yang digunakan efektif mencegah serangan rayap tanah C. curvignathus Holmgren dan rayap kayu kering C. cynocephalus Light. Efektivitas bahan pengawet dengan menyebabkan mortalitas rayap sebesar 100% diperoleh pada konsentrasi 1% dengan retensi masing-masing 6,01 kg/m3dan 5,64 kg/m3. Namun demikian terhadap jamur pelapuk kayu S. commune konsentrasi efektif diperoleh pada larutan 7,5% dengan retensi 45,44 kg/m3

Identifikasi Hama Kutu Putih pada Bibit Sengon (Falcataria Moluccana (Miq.) Barneby And J.W Grimes) di Persemaian Puslitbang Kehutanan

Commercial and community plantation of sengon commonly know as Moluccan albizia (Falcataria moluccana (Miq.) Barneby and J.W Grimes) requires qualified transplant, but the supply of such transplant seed is constrained by mealybug pest attack in the nursery. The purpose of this study is to identify the mealybug species that attack Moluccan albizia seeds. Observation of the symptoms mealybug attack in the nursery and identification of mealybug species has been performed in the nursery of Forest Research Center, Bogor. The results were mealybug that attack nursery was Ferrisia virgata belong to the famili Pseudococcidae, the Order Hemiptera. White mealybug colonized the stems and leaves of seeds. The leaves fall and plant wilted when the attack become serous. Predator Curinus coerulus and Coccinella repanda was suggested to be used to control mealybug

Keefektifan Campuran Garam Tembaga-khromium- Boron Terhadap Rayap Dan Jamur Perusak Kayu

Tujuan penelitian ini adalah mengevaluasi toksisitas formula garam tembaga-khromium-boron terhadap serangan rayap dan jamur Perusak kayu. Dalam penelitian ini digunakan bahan kimia kualitas teknis. Hasil pengujian menunjukkan bahwa bahan pengawet yang digunakan sangat efektif mencegah serangan rayap tanah Coptotermes curvignathus Holmgren dan rayap kayu kering Cryptotermes cynocephalus Light. Keefektifan ditunjukkan oleh tingkat mortalitas rayap 100% pada konsentrasi 1% dan retensi lebih dari 5,30 kg/m3. Namun demikian terhadap jamur pelapuk kayu Schizophyllum communekonsentrasi efektif diperoleh pada larutan 7,5% dan retensi di atas 30 kg/m3

Efektivitas Penularan Beberapa Isolat Jamur Patogen Serangga Metarbizium Anisopliae Oleh Rayap Pekerja Coptotermes Curvignathus

Jamur patogen serangga Metarhizium anisopliae diketahui bersifat patogen terhadap banyak serangga termasuk rayap. Penularan terjadi melalui penyebaran spora. Efektivitas penularan oleh kasta rayap pekerja Coptotermes curvignathus yang telah terinfeksi spora jamur dari 6 isolat yang dikumpulkan dari berbagai lokasi di Jawa dievaluasi. Beberapa kelompok rayap yang terdiri dari campuran rayap pekerja yang terinfeksi spora dan yang sehat dimasukkan dalam botol kultur berisi media pasir steril yang lembab, diinkubasi dalam ruang gelap dan lembab pada suhu kamar selama 14 hari. Hasil penelitian menunjukkan bahwa persentase mortalitas rayap cenderung meningkat setelah inkubasi dibandingkan dengan sebelum inkubasi. Isolat dari Balai Penelitian Bioteknologi Perkebunan Bogor (BGR), Fakultas Pertanian Universitas Gajah Mada Yogyakarta (UGM)p dan Balai Proteksi Tanaman Perkebunan Semarang (SMG) menunjukkan efektivitas penularan yang tinggi, menyebabkan mortalitas rayap lebih dari 80% pada perlakuan rayap terinfeksi dengan konsentrasi 50%. Isolat dari Bogor tampaknya paling efektif untuk ditularkan oleh rayap pekerja ke dalam koloninya

Carrier Transport mechanisms contributing to the sub-threshold current in 3C-SiC-on-Si Schottky Barrier Diodes

3C-Silicon Carbide (3C-SiC) Schottky Barrier Diodes on silicon (Si) substrates (3C-SiC-on-Si) seem not to comply with the superior wide band gap expectations in terms of excessive measured sub-threshold current. In turn, that is one of the factors which deters their commercialization. Interestingly, the forward biased part of the Current-Voltage (I-V) characteristics in these devices carries considerable information about the material quality. In this context, an advanced Technology Computer Aided Design (TCAD) model for a vertical Platinum/3C-SiC Schottky power diode is created and validated with measured data. The model includes defects originating from both the Schottky contact and the hetero-interface of 3C-SiC with Si which allows the investigation of their impact on the magnification of the sub-threshold current. For this, barrier lowering, quantum field emission and trap assisted tunneling of majority carriers need to be considered at the non-ideal Schottky interface. The simulation results and measured data allowed for the comprehensive characterization of the defects affecting the carrier transport mechanisms of the forward biased 3C-SiC on Si power rectifier for the first time

Health education and the control of urogenital schistosomiasis: assessing the impact of the Juma na Kichocho comic-strip medical booklet in Zanzibar

Endeavours to control urogenital schistosomiasis on Unguja Island (Zanzibar) have focused on school-aged children. To assess the impact of an associated health education campaign, the supervised use of the comic-strip medical booklet Juma na Kichocho by Class V pupils attending eighteen primary schools was investigated. A validated knowledge and attitudes questionnaire was completed at baseline and repeated one year later following the regular use of the booklet during the calendar year. A scoring system (ranging from 0.0 to 5.0) measured children's understandings of schistosomiasis and malaria, with the latter being a neutral comparator against specific changes for schistosomiasis. In 2006, the average score from 751 children (328 boys and 423 girls) was 2.39 for schistosomiasis and 3.03 for malaria. One year later, the score was 2.43 for schistosomiasis and 2.70 for malaria from 779 children (351 boys and 428 girls). As might be expected, knowledge and attitudes scores for schistosomiasis increased (+0.05), but not as much as originally hoped, while the score for malaria decreased (-0.33). According to a Kolmogorov-Smirnov test, neither change was statistically significant. Analysis also revealed that 75% of school children misunderstood the importance of reinfection after treatment with praziquantel. These results are disappointing. They demonstrate that it is mistaken to assume that knowledge conveyed in child-friendly booklets will necessarily be interpreted, and acted upon, in the way intended. If long-term sustained behavioural change is to be achieved, health education materials need to engage more closely with local understandings and responses to urogenital schistosomiasis. This, in turn, needs to be part of the development of a more holistic, biosocial approach to the control of schistosomiasis

Predicting invasion success in complex ecological networks

A central and perhaps insurmountable challenge of invasion ecology is to predict which combinations of species and habitats most effectively promote and prevent biological invasions. Here, we integrate models of network structure and nonlinear population dynamics to search for potential generalities among trophic factors that may drive invasion success and failure. We simulate invasions where 100 different species attempt to invade 150 different food webs with 15–26 species and a wide range (0.06–0.32) of connectance. These simulations yield 11 438 invasion attempts by non-basal species, 47 per cent of which are successful. At the time of introduction, whether or not the invader is a generalist best predicts final invasion success; however, once the invader establishes itself, it is best distinguished from unsuccessful invaders by occupying a lower trophic position and being relatively invulnerable to predation. In general, variables that reflect the interaction between an invading species and its new community, such as generality and trophic position, best predict invasion success; however, for some trophic categories of invaders, fundamental species traits, such as having the centre of the feeding range low on the theoretical niche axis (for non-omnivorous and omnivorous herbivores), or the topology of the food web (for tertiary carnivores), best predict invasion success. Across all invasion scenarios, a discriminant analysis model predicted successful and failed invasions with 76.5 per cent accuracy for properties at the time of introduction or 100 per cent accuracy for properties at the time of establishment. More generally, our results suggest that tackling the challenge of predicting the properties of species and habitats that promote or inhibit invasions from food web perspective may aid ecologists in identifying rules that govern invasions in natural ecosystems

The effects of tryptophan loading on Attention Deficit Hyperactivity in adults:A remote double blind randomised controlled trial

BackgroundDespite the impact and prevalence of Attention Deficit Hyperactivity Disorder (ADHD), current treatment options remain limited and there is a drive for alternative approaches, including those building on evidence of a role for tryptophan (TRP) and serotonin (5-HT). This study aimed to evaluate the effect of acute TRP loading on attention and impulsivity in adults with ADHD.Trial design and methods We conducted a remote double blind randomised controlled trial (RCT) using TRP loading to examine the effects of a balanced amino acid load in comparison to low and high TRP loading in individuals with ADHD (medicated, N = 48, and unmedicated, N = 46) and controls (N = 50). Participants were randomised into one of three TRP treatment groups using stratified randomisation considering participant group and gender using a 1:1:1 ratio. Baseline testing of attention and impulsivity using the Test of Variables of Attention Task, Delay Discounting Task, and Iowa Gambling Task was followed by consumption of a protein drink (BAL, LOW, or HIGH TRP) before repeated testing. Results and ConclusionsNo effects of TRP were observed for any of the measures. In the present study, TRP loading did not impact on any measure of attention or impulsivity in those with ADHD or Controls. The findings need to be confirmed in another trial with a larger number of patients that also considers additional measures of dietary protein, plasma TRP and aggression. (Registration ID ISRCTN15119603)<br/