Performa Reproduksi Ikan Sepat Siam (Trichopoduspectoralis Regan 1910) Asal Sumatera, Jawa, Dan Kalimantan [Reproduction Performance of Snakeskin Gouramy (Trichopodus Pectoralis Regan 1910) From Sumatera, Jawa and Kalimantan]

Ikan sepat siam Trichopodus pectoralis merupakan ikan potensial budi daya. Salah satu masalah utama yang sedang di-hadapi ikan ini adalah adanya penurunan populasi. Domestikasi ikan sepat siam diperlukan agar pengembangbiakan melalui kegiatan budi daya dapat dilakukan untuk mengatasi kelangkaan dan menjaga kelestariannya. Tujuan penelitian ini adalah untuk mengevaluasi performa reproduksi yang merupakan salah satu aspek penting dalam domestikasi. Eva-luasi dilakukan pada ikan sepat siam potensial dari Lampung, Jawa Timur, dan Kalimantan Barat. Pemijahan telah dila-kukan secara alami. Penelitian ini dilakukan di Laboratorium Basah Balai Penelitian dan Pengembangan Budidaya Air Tawar Bogor dari bulan September sampai dengan Desember 2013. Karakter reproduksi antara lain: fekunditas, derajat pembuahan, derajat penetasan, dan sintasan larva dihitung berdasar satu kali sampling dan dianalisis secara deskriptif. Fase perkembangan awal ikan diamati dengan menggunakan metode mikroskopi. Hasil menunjukkan bahwa fekunditas dan sintasan larva tertinggi didapatkan oleh ikan sepat siam asal Kalimantan Barat. Perkembangan awal menunjukkan tidak adanya keabnormalan. Fase segmentasi dan penetasan merupakan fase kritis pada perkembangan awal ikan sepat siam

Keragaan Hibridaintra Spesifik Dariempat Strain Ikan Nila (Oreochromis Niloticus) Dikaramba Jaring Apung, Danau Lido, Bogor [Performance of Four Intraspesific Hybridization of Nile Tilapine {Oreochromis Niloticus) in Experimental Floating Net Cages in Lake Lido]

The objectives of the study was to evaluate hybrid performance of sixteen reciprocal cross resulted from three strains (Red NIFI,Nirwana, BEST) and one population (Lido Lake population) of nile tilapi. The study was conducted in experimental floating netcages in Lido Lake. Fish of 25 days old ranged 0,4 ± 0.07 g were used in the experiment. Fish were reared in floating net cages sized 2x1x1 m for each cross with the density of 50 fish/cage for eight weeks (56 days). Feed were given 10% of body weight with frequency three times a day. The results showed that the highest average larvae production was 1216 from Nirwana female crossed with four different male. Growth rate of hybrids were higher than the parents (P < 0.05) and the highest was .ed NIFI x c? BEST (6,440±0,0712% ).The highest survival rate was $ Red Lido x S BEST hybrid (77.0 ±2,78%")). For heterosis, Specific Growth Rate (SGR) was 5.8188% on hybrid between Nirwana and Red Lido. While for survival rate was 15.5888% on Nirwana x BEST hybrid. Crossing between fenotipe of light color background (red) and dark color background (black) showed that red color was dominant to the black one. Pleiotric effect of color gen was detected on the SGR and survival rate

Directed cell migration in the presence of obstacles

BACKGROUND: Chemotactic movement is a common feature of many cells and microscopic organisms. In vivo, chemotactic cells have to follow a chemotactic gradient and simultaneously avoid the numerous obstacles present in their migratory path towards the chemotactic source. It is not clear how cells detect and avoid obstacles, in particular whether they need a specialized biological mechanism to do so. RESULTS: We propose that cells can sense the presence of obstacles and avoid them because obstacles interfere with the chemical field. We build a model to test this hypothesis and find that this naturally enables efficient at-a-distance sensing to be achieved with no need for a specific and active obstacle-sensing mechanism. We find that (i) the efficiency of obstacle avoidance depends strongly on whether the chemotactic chemical reacts or remains unabsorbed at the obstacle surface. In particular, it is found that chemotactic cells generally avoid absorbing barriers much more easily than non-absorbing ones. (ii) The typically low noise in a cell's motion hinders the ability to avoid obstacles. We also derive an expression estimating the typical distance traveled by chemotactic cells in a 3D random distribution of obstacles before capture; this is a measure of the distance over which chemotaxis is viable as a means of directing cells from one point to another in vivo. CONCLUSION: Chemotactic cells, in many cases, can avoid obstacles by simply following the spatially perturbed chemical gradients around obstacles. It is thus unlikely that they have developed specialized mechanisms to cope with environments having low to moderate concentrations of obstacles

Sequential decoupling of negative-energy states in Douglas-Kroll-Hess theory

Here, we review the historical development, current status, and prospects of Douglas--Kroll--Hess theory as a quantum chemical relativistic electrons-only theory.Comment: 15 page

Changes in the serum proteome associated with the development of hepatocellular carcinoma in hepatitis C-related cirrhosis

Early diagnosis of hepatocellular carcinoma (HCC) is the key to the delivery of effective therapies. The conventional serological diagnostic test, estimation of serum alpha-fetoprotein (AFP) lacks both sensitivity and specificity as a screening tool and improved tests are needed to complement ultrasound scanning, the major modality for surveillance of groups at high risk of HCC. We have analysed the serum proteome of 182 patients with hepatitis C-induced liver cirrhosis (77 with HCC) by surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI). The patients were split into a training set (84 non-HCC, 60 HCC) and a ‘blind' test set (21 non-HCC, 17 HCC). Neural networks developed on the training set were able to classify the blind test set with 94% sensitivity (95% CI 73–99%) and 86% specificity (95% CI 65–95%). Two of the SELDI peaks (23/23.5 kDa) were elevated by an average of 50% in the serum of HCC patients (P<0.001) and were identified as κ and λ immunoglobulin light chains. This approach may permit identification of several individual proteins, which, in combination, may offer a novel way to diagnose HCC

Preclinical and post-treatment changes in the HCC-associated serum proteome

SELDI-based proteomic profiling of body fluids is currently in widespread use for cancer biomarker discovery. We have successfully used this technology for the diagnosis of hepatocellular carcinoma (HCC) in hepatitis C patients and now report its application to serial serum samples from 37 hepatitis C patients before development of HCC, with HCC and following radiofrequency ablation of the tumour. As with alpha-fetoprotein, an accepted biomarker for HCC, we hypothesised that HCC-associated proteomic features would ‘return to normal' following successful treatment and the primary aim of our study was to test this hypothesis. Several SELDI peaks that changed significantly during HCC development were detected but they did not reverse following treatment. These data may be interpreted to suggest that the characteristic SELDI profile is not linearly related to tumour burden but may result from the progression of underlying liver disease or from the emergence of precancerous lesions. β2-Microglobulin, a protein previously reported to be markedly elevated in patients with HCV related HCC, was also the most significantly HCC associated proteomic feature (m/z 11720) in this study

Novel Methods for Analysing Bacterial Tracks Reveal Persistence in Rhodobacter sphaeroides

Tracking bacteria using video microscopy is a powerful experimental approach to probe their motile behaviour. The trajectories obtained contain much information relating to the complex patterns of bacterial motility. However, methods for the quantitative analysis of such data are limited. Most swimming bacteria move in approximately straight lines, interspersed with random reorientation phases. It is therefore necessary to segment observed tracks into swimming and reorientation phases to extract useful statistics. We present novel robust analysis tools to discern these two phases in tracks. Our methods comprise a simple and effective protocol for removing spurious tracks from tracking datasets, followed by analysis based on a two-state hidden Markov model, taking advantage of the availability of mutant strains that exhibit swimming-only or reorientating-only motion to generate an empirical prior distribution. Using simulated tracks with varying levels of added noise, we validate our methods and compare them with an existing heuristic method. To our knowledge this is the first example of a systematic assessment of analysis methods in this field. The new methods are substantially more robust to noise and introduce less systematic bias than the heuristic method. We apply our methods to tracks obtained from the bacterial species Rhodobacter sphaeroides and Escherichia coli. Our results demonstrate that R. sphaeroides exhibits persistence over the course of a tumbling event, which is a novel result with important implications in the study of this and similar species

Ultrafast structure and dynamics in ionic liquids: 2D-IR spectroscopy probes the molecular origin of viscosity

The viscosity of imidazolium ionic liquids increases dramatically when the strongest hydrogen bonding location is methylated. In this work, ultrafast two-dimensional vibrational spectroscopy of dilute thiocyanate ion ([SCN] -) in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4C1im][NTf2]) and 1-butyl-2,3- dimethylimidazolium bis(trifluoromethylsulfonyl)imide ([C4C 1C12im][NTf2]) shows that the structural reorganization occurs on a 26 ± 3 ps time scale and on a 47 ± 15 ps time scale, respectively. The results suggest that the breakup of local ion-cages is the fundamental event that activates molecular diffusion and determines the viscosity of the fluids. © 2014 American Chemical Society

Spatial Pattern Enhances Ecosystem Functioning in an African Savanna

Termites indirectly enhance plant and animal productivity near their mounds, and the uniform spatial patterning of these mounds enhances the overall productivity of the entire landscape