Field-Induced Breakup of Emulsion Droplets Stabilized by Colloidal Particles

We simulate the response of a particle-stabilized emulsion droplet in an external force field, such as gravity, acting equally on all $N$ particles. We show that the field strength required for breakup (at fixed initial area fraction) decreases markedly with droplet size, because the forces act cumulatively, not individually, to detach the interfacial particles. The breakup mode involves the collective destabilization of a solidified particle raft occupying the lower part of the droplet, leading to a critical force per particle that scales approximately as $N^{-1/2}$.Comment: 4 pages, plus 3 pages of supplementary materia

Expression and Action of Transforming Growth Factor Beta (TGFβ1, TGFβ2, and TGFβ3) during Embryonic Rat Testis Development1

The objective of the current study was to determine the role of transforming growth factor beta (TGF) during seminiferous cord formation and embryonic testis development. The expression pattern of mRNA for TGF isoforms was evaluated during testis development through a quantitative reverse transcription-polymerase chain reaction (QRT-PCR) procedure. Expression of mRNA for TGF1 was highest at postnatal day 0 (P0) and P10. In contrast, TGF2 was high at embryonic day 15 (E15), declined at E16, and showed a transient increase at P0 through P3 of testis development. Interestingly, expression of mRNA for TGF3 was high during embryonic development and then declined after P3. Immunohistochemical localization of TGF1 and TGF2 demonstrated expression in Sertoli cells at E14 and in the seminiferous cords at P0. Selective interstitial cells expressed high concentrations of TGF1 and TGF2 in P0 testis. TGF3 was expressed in selective cells at the junction of the E14 testis and mesonephros. The cells expressing TGF3 in the testis appeared to be preperitubular cells that resided around the seminiferous cords. TGF3 was localized to gonocytes in P0 testis. TGF1 was found to have no influence on seminiferous cord formation in embryonic organ cultures of E13 testis. In contrast, growth of both E13 and E14 embryonic organ cultures was inhibited by TGF1 and resulted in reduced testis size (40% of controls) with fewer cords present. A P0 testis cell culture and thymidine incorporation assay were used to directly examine the effects of recombinant TGF1. TGF1 alone had no influence on thymidine incorporation in P0 testis cell cultures when compared to controls. Interestingly, TGF1 inhibited epi-dermal growth factor (EGF), and 10% calf serum stimulated P0 testis cell growth but not FSH-stimulated growth. Therefore, TGF1 appears to inhibit testis growth in both the embryonic and early postnatal periods. The hormonal regulation of TGF expression was measured using P0 testis cell cultures and a QRT-PCR procedure for each TGF isoform. High concentrations of EGF stimulated expression of mRNA for TGF1 after 24 h but suppressed expression of TGF3. In contrast, there was no effect of FSH on TGF isoform expression. In summary, TGF regulates embryonic and P0 testis growth through inhibiting the actions of positive growth factors such as EGF. In addition, EGF but not FSH appears to regulate TGF isoform expression. Combined observations from the present study demonstrate that TGF iso-forms are differentially expressed and appear to be regulators of testis growth during the embryonic and early postnatal periods

Energy Gradients Structure Microbial Communities Across Sediment Horizons in Deep Marine Sediments of the South China Sea

The deep marine subsurface is a heterogeneous environment in which the assembly of microbial communities is thought to be controlled by a combination of organic matter deposition, electron acceptor availability, and sedimentology. However, the relative importance of these factors in structuring microbial communities in marine sediments remains unclear. The South China Sea (SCS) experiences significant variability in sedimentation across the basin and features discrete changes in sedimentology as a result of episodic deposition of turbidites and volcanic ashes within lithogenic clays and siliceous or calcareous ooze deposits throughout the basin\u27s history. Deep subsurface microbial communities were recently sampled by the International Ocean Discovery Program (IODP) at three locations in the SCS with sedimentation rates of 5, 12, and 20 cm per thousand years. Here, we used Illumina sequencing of the 16S ribosomal RNA gene to characterize deep subsurface microbial communities from distinct sediment types at these sites. Communities across all sites were dominated by several poorly characterized taxa implicated in organic matter degradation, including Atribacteria, Dehalococcoidia, and Aerophobetes. Sulfate-reducing bacteria comprised only 4% of the community across sulfate-bearing sediments from multiple cores and did not change in abundance in sediments from the methanogenic zone at the site with the lowest sedimentation rate. Microbial communities were significantly structured by sediment age and the availability of sulfate as an electron acceptor in pore waters. However, microbial communities demonstrated no partitioning based on the sediment type they inhabited. These results indicate that microbial communities in the SCS are structured by the availability of electron donors and acceptors rather than sedimentological characteristics

Expression and Action of Neurotropin-3 and Nerve Growth Factor in Embryonic and Early Postnatal Rat Testis Development

The current study examines the expression and potential actions of neurotropin-3 (NT3), nerve growth factor (NGF), and their receptors during morphological sex determination (seminiferous cord formation) and perinatal rat testis development. The expression of neurotropins and their receptors was analyzed with immunohistochemistry. Cellular localization of neurotropin ligand and receptor proteins changed during embryonic testis development. Neurotropin-3 was localized to Sertoli cells at Embryonic Day 14 (E14), was present in gonocytes at Postnatal Day 0 (P0), and after birth became localized to the interstitium and Sertoli cells (P3–P5). The expression of trk C (the high affinity receptor for NT3) was localized to mesonephric ducts and cells surrounding the cords (E14–E18). In addition, Sertoli cells and preperitubular cells surrounding the cords at E14 also stained for trk C. Neurotropin-3 was expressed in gonocytes and Sertoli cells at P0–P5. Nerve growth factor was detected in Sertoli cells at E14, was clearly in Sertoli and interstitial cells at E16 and E18, and in Sertoli, germ, and interstitial cells from P0–P5. The expression of trk A (the high affinity receptor for NGF) was located in Sertoli and interstitial cells at E16–P5. To determine the actions of neurotropins during embryonic and perinatal testis development, experiments were conducted on E13 and P0 testis. Antisense oligonucleotide experiments with NT3 were used on E13 testis organ cultures to determine effects on seminiferous cord formation. Cord formation was inhibited in 40% of the organ cultures treated with the antisense NT3 oligonucleotides, while no inhibition was observed with sense oligonucleotides. In P0 testis cultures, both NT3 and NGF alone and in combination stimulated thymidine incorporation into DNA. Therefore, the neurotropins are involved in embryonic morphological events (cord formation; NT3) and in growth of the perinatal testis (P0; NT3 and NGF). To define further the growth effects of neurotropins on testis development, expression of transforming growth factor alpha and beta (TGFα and TGFβ) were examined in response to neurotropins. The P0 testis cultures were treated with neurotropins, and expression of mRNA for TGFα and TGFβ was analyzed utilizing a quantitative reverse transcription-polymerase chain reaction assay. Nerve growth factor and NT3 alone or in combination inhibited expression of mRNA for TGFα while NT3 increased mRNA expression of epidermal growth factor receptor. The combination treatment of neurotropins inhibited expression of TGFβ1 and increased expression of TGFβ3. In summary, observations suggest that NT3, NGF, trk A, and trk C are localized to cells critical to seminiferous cord formation and appear to be important regulators of morphological sex determination. In addition to these morphological effects, both NT3 and NGF stimulate P0 testis growth and may elicit their action through altering the expression of locally produced growth factors such as TGFα and TGFβ. Taken together these results suggest that neurotropins are regulators of paracrine cell-cell interactions that result in morphological sex determination and perinatal testis growth

HIV-1 Tat stimulates transcription complex assembly through recruitment of TBP in the absence of TAFs

The human immunodeficiency virus type I (HIV-1) transactivator protein Tat is an unusual transcriptional activator that is thought to act solely by promoting RNA polymerase II processivity. Here we study the mechanism of Tat action by analyzing transcription complex (TC) assembly in vivo using chromatin immunoprecipitation assays. We find, unexpectedly, that like typical activators Tat dramatically stimulates TC assembly. Surprisingly, however, the TC formed on the HIV-1 long terminal repeat is atypical and contains TATA-box-binding protein (TBP) but not TBP-associated factors (TAFs). Tat function involves direct interaction with the cellular cofactor positive transcription elongation factor b (P-TEFb). Artificial tethering of P-TEFb subunits to HIV-1 promoter DNA or nascent RNA indicates that P-TEFb is responsible for directing assembly of a TC containing TBP but not TAFs. On the basis of this finding, we identify P-TEFb-dependent cellular promoters that also recruit TBP in the absence of TAFs. Thus, in mammalian cells transcription of protein-coding genes involves alternative TCs that differ by the presence or absence of TAFs

DEVELOPMENT OF NIPA (Nypa fruticans) SAP CLOSED COLLECTION VESSEL

The ultimate goal of the present study was to develop a secure, safe, and hygienic nipa sap collection system for bioethanol production, with the aim of preserving its physico-chemical properties such as physical appearance, pH and sugar brix by reducing the rate of fermentation while attached to the peduncle. The developed collection system was evaluated in terms of the physical and chemical properties of nipa sap collected and ethanol yield in comparison to the traditional and existing collection system used by the nipa community which utilizes bamboo shingle as their collector. Physical appearance of the sap collected using the designed collection system had no foreign materials after harvesting while the traditional collection system had shown traces of insect infestation. The sap that was produced for both of the designed and traditional collection system was milky-white and yellowish-white in color respectively. There was a significant difference in terms of pH concentration of the sap collected using the designed collection system compared to the sap collected using the traditional system overtime. Sugar brix of nipa sap collected using designed collection system is significantly higher than the sap collected using traditional system. A total ethanol yield of 32.25% and 75.54% was obtained for the designed and traditional collection system respectively. Cost Analysis revealed that the designed collection system was found to be cheaper (PhP 11.93) than the traditional collection system (PhP. 20.00). The developed closed collection system can preserved the chemical properties of the nipa sap and could prevent acceleration of fermentation and the deterioration of its potential to yield more ethanol

Three-Dimensional Geometric Morphometric Analysis of Fossil Canid Mandibles and Skulls

Acknowledgements We thank C.P. Klingenberg for critical discussion of methodology. A. Drake and R. Losey were supported by a grant from the Social Sciences and Humanities Research Council of Canada grant (#SSHRC IG 435-2014-0075) and a European Research Council Grant to D. Anderson (#295458). M. Sablin acknowledges participation of ZIN RAS (state assignment № АААА-А17-117022810195-3) to this research. Supplementary information accompanies this paper at doi:10.1038/s41598-017-10232-1Peer reviewedPublisher PD

Mapping the UK thesis landscape: Phase 1 project report for Unlocking Thesis Data

This report details the work of the first phase (April-July 2015) of Unlocking Thesis Data, where the project carried out a survey of EThOS institutions, interviewed staff at six universities for more in-depth case studies, and synthesised the findings. Overall, there is much appetite for applying DOIs to theses and their data (which includes datasets, software components and other non-textual supplementary files) and ORCiDs to research students. Glasgow, Southampton and East London universities each minted a DOI for an existing thesis, demonstrating the viability of our intent, but the case studies showed there are constraints in both processes and technologies to be addressed before persistent identifiers (PID) for theses can be a nationwide reality in the UK. The project makes five recommendations for further work in a second phase: 1. Hold at least three thesis “clinics” to investigate opportunities and barriers to assigning DOI and ORCiD identifiers in UK universities 2. Engage with system suppliers/vendors to identify opportunities for enhancing software with required PIDs 3. Consult with EThOS formally to understand what needs to change in EThOS systems and processes to harvest and display PIDs and related metadata for theses and their data 4. Evaluate approaches to updating UKETD profile, initially in EPrints, before planning software enhancements 5. Investigate requirements and solutions for those institutions that use EThOS as their first-point repository