The PSI-U1 snRNP interaction regulates male mating behavior in Drosophila

Alternative pre-mRNA splicing (AS) is a critical regulatory mechanism that operates extensively in the nervous system to produce diverse protein isoforms. Fruitless AS isoforms have been shown to influence male courtship behavior, but the underlying mechanisms are unknown. Using genome-wide approaches and quantitative behavioral assays, we show that the P-element somatic inhibitor (PSI) and its interaction with the U1 small nuclear ribonucleoprotein complex (snRNP) control male courtship behavior. PSI mutants lacking the U1 snRNP-interacting domain (PSIΔAB mutant) exhibit extended but futile mating attempts. The PSIΔAB mutant results in significant changes in the AS patterns of ∼1,200 genes in the Drosophila brain, many of which have been implicated in the regulation of male courtship behavior. PSI directly regulates the AS of at least one-third of these transcripts, suggesting that PSI-U1 snRNP interactions coordinate the behavioral network underlying courtship behavior. Importantly, one of these direct targets is fruitless, the master regulator of courtship. Thus, PSI imposes a specific mode of regulatory control within the neuronal circuit controlling courtship, even though it is broadly expressed in the fly nervous system. This study reinforces the importance of AS in the control of gene activity in neurons and integrated neuronal circuits, and provides a surprising link between a pleiotropic pre-mRNA splicing pathway and the precise control of successful male mating behavior

Stanilov-Tsankov-Videv Theory

We survey some recent results concerning Stanilov-Tsankov-Videv theory, conformal Osserman geometry, and Walker geometry which relate algebraic properties of the curvature operator to the underlying geometry of the manifold.Comment: This is a contribution to the Proceedings of the 2007 Midwest Geometry Conference in honor of Thomas P. Branson, published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA

Organic Carbon Burial following the Middle Eocene Climatic Optimum (MECO) in the central - western Tethys

We present trace metal geochemistry and stable isotope records for the middle Eocene Alano di Piave section, NE Italy, deposited during magnetochron C18n in the marginal Tethys Ocean. We identify a $\sim$ 500 kyr long carbon isotope perturbation event we infer to be the middle Eocene Climatic Optimum (MECO) confirming the northern hemisphere expression and global occurrence of MECO. Interpreted peak climatic conditions are followed by the rapid deposition of two organic rich intervals ($\le$3\% TOC) and contemporaneous positive $\delta^{13}$C excursions. These two intervals are associated with increases in the concentration of sulphur and redox-sensitive trace metals, and low concentrations of Mn, as well as coupled with the occurrence of pyrite. Together these changes imply low, possibly dysoxic, bottom water O$_{2}$ conditions promoting increased organic carbon burial. We hypothesize that this rapid burial of organic carbon lowered global {\it p}CO$_{2}$ following the peak warming and returned the climate system to the general Eocene cooling trend

Eocene biostratigraphy and magnetic stratigraphy from Possagno, Italy: The calcareous nannofossil response to climate variability

A study of quantitative calcareous nannofossil biostratigraphy and magnetostratigraphy of a ∼ 68-m-thick marine limestone section of Late Paleocene–Middle Eocene age outcropping at Possagno in northern Italy shows that the section encompasses nannofossil Zones NP9–NP15 (equivalent to CP8–CP13b) and Chrons C24r–C21n. The Paleocene–Eocene boundary was placed at the base a of δ13C negative excursion from the literature that was found virtually coincident with the base of Zone NP9b. The base of the Middle Eocene (Lutetian) was placed at the base of Chron C21r. Biostratigraphic events were generally found to be consistent with parallel events in recent time scales; several potentially useful new events are also described. In particular, we detected the earliest specimens of Dictyococcites at the base of Chron C22r (NP12–NP13 zonal transition), which is several million years older than previous estimates. Correlation of Possagno data to the oxygen isotope record from the literature allowed us to describe the temporal relationships between climate variability and calcareous nannofossil assemblages. Modifications in the nannofossil assemblage coeval to both the Paleocene–Eocene Thermal Maximum (PETM) and the Early–Middle Eocene long-term climatic trend are recognized. The short-lived PETM was coeval to provisional adaptations (malformations and/or ecophenotypes) in the coccolithophores communities that were reabsorbed upon return to long-term varying climatic conditions. The Early–Middle Eocene long-term climatic trend was instead coeval to true evolutionary trends with the appearance of the very successful Noelaerhabdaceae clade whose offsprings include the most important bloom-forming coccolithophorids in the modern ocean. The Early–Middle Eocene can thus be considered the time in which nannoplankton communities set course toward modern structure triggering a reconfiguration of the global ocean life chain

Mapping of Mangrove Diversity in Kelurahan Tongkaina, Bunaken Sub-District, Manado

This research was conducted in coastal area of Tongkaina Village, Bunaken Sub-district, Manado City, North Sulawesi Province. The purpose of this study was to calculate the diversity of mangrove plants and map the zoning of mangrove species distribution in three research sites. The data collected are categorized as primary and secondary data. Primary data collection related to biophysical condition of mangrove ecosystem, including vegetation structure and area of mangrove cover in study site and further analyzed. Secondary data were collected from various literature studies, documentation and scientific papers and related legislation. Based on  the obtained results, it was known that the diversity index of mangrove in Tongkaina is 1.71 which is categorized as medium in term of its diversity, because the value of H 'is greater than 1 and smaller than 3. This value means also that there was enough productivity, ecosystem condition is quite balanced, and moderate ecological pressures. The highest species diversity index was found in Sonneratia alba with an index of 0.37 and the lowest was in the Bruguiera gymnorrhiza species with index of 0.06. Mapping of mangrove species is done by taking coordinate points within quadrant at three research sites. Color degradation with rounded symbols are used to distinguish each species. The aims are designed to be able to easily distinguish between species visually and can be used as one method of mapping study on the diversity of mangroves. This study reveals the known levels of mangrove diversity are moderate. The existence of fishing activities and mooring boat by the local community contribute to mangrove land degradation. Indispensable protection or conservation through knowledge transfer and building awareness to the community, as well as providing an economic alternative for those utilizing mangrove for both household and commercial needs, in order to maintain better conditions are equally important.Keywords: Mapping, Mangrove, Diversity, TongkainaAbstrakPenelitian ini berlokasi di kawasan pesisir pantai Kelurahan Tongkaina, Kecamatan Bunaken Kota Manado Provinsi Sulawesi Utara. Tujuan dari penelitian ini yaitu untuk menghitung keanekaragaman hutan mangrove serta memetakan zonasi pembagian jenis mangrove di tiga stasiun penelitian. Data yang dikumpulkan adalah data primer dan data sekunder. Pengumpulan data primer berkaitan dengan kondisi biofisik ekosistem mangrove yaitu, struktur vegetasi dan luasan mangrove di daerah penelitian dan selanjutnya dianalisis. Kemudian data sekunder dikumpulkan dari berbagai kajian literature, dokumentasi dan tulisan-tulisan ilmiah serta peraturan perundang-undangan terkait. Pada hasil yang diperoleh diketahui nilai indeks keanekaragaman mangrove di Tongkaina adalah 1,71 dimana nilai indeks ini tergolong dalam kategori keanekaragaman sedang, karena nilai H’ lebih besar dari 1 dan lebih kecil dari 3, yang berarti produktivitas cukup, kondisi ekosistem cukup seimbang, dan tekanan ekologis sedang. Indeks Keanekaragaman spesies tertinggi didapati pada Sonneratia alba dengan nilai indeks 0,37 dan terendah ada pada spesies Bruguiera gymnorrhiza yang memiliki nilai indeks yaitu 0,06. Pemetaan jenis mangrove dilakukan dengan cara pengambilan titik koordinat pada kuadran di tiga stasiun penelitian. Degradasi warna dengan simbol bulat di pakai untuk membedakan tiap spesies. Hal ini bertujuan agar dapat dengan mudah membedakan antar spesies secara visual serta dapat dijadikan salah satu metode kajian untuk memetakan keanekaragaman mangrove. Diketahui tingkat keanekaragaman mangrove tergolong sedang. Adanya kegiatan pertambakan dan tambatan perahu masyarakat membuat lahan mangrove semakin berkurang. Sangat diperlukan adanya perlindungan atau pelestarian melalui pengetahuan dan penyadaran kepada masyarakat, serta memberikan alternatif ekonomi bagi yang memanfaatkan mangrove baik untuk kebutuhan rumah tangga ataupun komersial, demi menjaga perkembangan kondisi yang lebih baik.Kata kunci:      Pemetaan, Mangrove, Keanekaragaman, Tongkain

ATRA mechanically reprograms pancreatic stellate cells to suppress matrix remodelling and inhibit cancer cell invasion

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a dismal survival rate. Persistent activation of pancreatic stellate cells (PSCs) can perturb the biomechanical homoeostasis of the tumour microenvironment to favour cancer cell invasion. Here we report that ATRA, an active metabolite of vitamin A, restores mechanical quiescence in PSCs via a mechanism involving a retinoic acid receptor beta (RAR-β)-dependent downregulation of actomyosin (MLC-2) contractility. We show that ATRA reduces the ability of PSCs to generate high traction forces and adapt to extracellular mechanical cues (mechanosensing), as well as suppresses force-mediated extracellular matrix remodelling to inhibit local cancer cell invasion in 3D organotypic models. Our findings implicate a RAR-β/MLC-2 pathway in peritumoural stromal remodelling and mechanosensory-driven activation of PSCs, and further suggest that mechanical reprogramming of PSCs with retinoic acid derivatives might be a viable alternative to stromal ablation strategies for the treatment of PDAC