The Regulation of Trading Markets: A Survey and Evaluation

This chapter was prepared for a conference exploring the desirability and structure of a new special study of the securities markets. Our objective is not to resolve all of the questions that commentators have raised about the new equity markets, but to lay the groundwork for a new special study by surveying the state of market regulation, identifying issues, and offering preliminary evaluations

Advantages and Disadvantages of Traditional Abaca, Genetically Modified Abaca, and Cross Hybrid Abaca

Abaca (Musa Textilis Née), also known as Manila hemp, is a plant native to the Philippines, which expanded through different parts of Asia. It is a biodegradable and sustainable source of fiber known for its high quality. Due to viruses, poor government support, and lack of fundings, the abaca fiber industry is encountering obstacles in keeping up with the global demands. Over time, researchers developed new abaca types such as crossbred abaca and genetically modified abaca to solve these problems, but these have their own deficiencies as well. The purpose of the study was to identify, assess, and elaborate on the advantages and disadvantages of each of the abaca types. This was accomplished through the evaluation of literature and the collection of data in interviews. The study was a systematic review focusing on meta-synthesis, with information derived from previously published research or related literature and information from experts in the field. It was determined that traditional abaca is vastly preferred over genetically modified abaca and cross hybrid abaca, due to a number of reasons, including lack of research and economic viability. Traditional abaca was found to be more sustainable overall. It was recommended that traditional abaca should be promoted more to spread awareness, and that farmers should be educated regarding the proper process of caring for abaca plants. Stigma regarding cross hybrid and genetically modified abaca should be addressed as well

Revisiting the hyperdominance of Neotropical tree species under a taxonomic, functional and evolutionary perspective

Recent studies have leveraged large datasets from plot-inventory networks to report a phenomenon of hyperdominance in Amazonian tree communities, concluding that few species are common and many are rare. However, taxonomic hypotheses may not be consistent across these large plot networks, potentially masking cryptic diversity and threatened rare taxa. In the current study, we have reviewed one of the most abundant putatively hyperdominant taxa, Protium heptaphyllum (Aubl.) Marchand (Burseraceae), long considered to be a taxonomically difficult species complex. Using morphological, genomic, and functional data, we present evidence that P. heptaphyllum sensu lato may represent eight separately evolving lineages, each warranting species status. Most of these lineages are geographically restricted, and few if any of them could be considered hyperdominant on their own. In addition, functional trait data are consistent with the hypothesis that trees from each lineage are adapted to distinct soil and climate conditions. Moreover, some of the newly discovered species are rare, with habitats currently experiencing rapid deforestation. We highlight an urgent need to improve sampling and methods for species discovery in order to avoid oversimplified assumptions regarding diversity and rarity in the tropics and the implications for ecosystem functioning and conservation

Modal Q Factor and Modal Overlap of Electrically Small Avionics Box

Estimating the electromagnetic field strength in avionics boxes and other small enclosures at the design stage requires an estimate of the Q factor of the cavity modes. When the enclosure is small, it is typically under-moded so that Q measurement techniques which are standard practice in over-moded reverberation chambers may not be a robust measure. Furthermore, practical antenna used to measure Q in a small cavity may have a strong influence on the result obtained, as reported by Tait et al, IEEE Trans. EMC 55 2 2012. This paper reports the results of testing to determine the Q factor of a small aperture enclosure, used in a statistical power balance model to predict the electric field strength. The contributors to the total Q are identified. A novel S(sub 11) curve fitting method to measure modal Q is introduced and compared with the time domain method for measuring Q

Incidence and Outcomes of Acute Implant Extrusion Following Anterior Cervical Spine Surgery.

STUDY DESIGN: Multi-institutional retrospective case series of 8887 patients who underwent anterior cervical spine surgery. OBJECTIVE: Anterior decompression from discectomy or corpectomy is not without risk. Surgical morbidity ranges from 9% to 20% and is likely underreported. Little is known of the incidence and effects of rare complications on functional outcomes following anterior spinal surgery. In this retrospective review, we examined implant extrusions (IEs) following anterior cervical fusion. METHODS: A retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, were reviewed to identify occurrence of 21 predefined treatment complications. RESULTS: Following anterior cervical fusion, the incidence of IE ranged from 0.0% to 0.8% across 21 institutions with 11 cases reported. All surgeries involved multiple levels, and 7/11 (64%) involved either multilevel corpectomies or hybrid constructs with at least one adjacent discectomy to a corpectomy. In 7/11 (64%) patients, constructs ended with reconstruction or stabilization at C7. Nine patients required surgery for repair and stabilization following IE. Average length of hospital stay after IE was 5.2 days. Only 2 (18%) had residual deficits after reoperation. CONCLUSIONS: IE is a very rare complication after anterior cervical spine surgery often requiring revision. Constructs requiring multilevel reconstruction, especially at the cervicothoracic junction, have a higher risk for failure, and surgeons should proceed with caution in using an anterior-only approach in these demanding cases. Surgeons can expect most patients to regain function after reoperation

Spatial variation of hydroclimate in north-eastern North America during the last millennium

Climatic expressions of the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA) vary regionally, with reconstructions often depicting complex spatial patterns of temperature and precipitation change. The characterisation of these spatial patterns helps advance understanding of hydroclimate variability and associated responses of human and natural systems to climate change. Many regions, including north-eastern North America, still lack well-resolved records of past hydrological change. Here, we reconstruct hydroclimatic change over the past millennium using testate amoeba-inferred peatland water table depth reconstructions obtained from fifteen peatlands across Maine, Nova Scotia, Newfoundland and Québec. Spatial comparisons of reconstructed water table depths reveal complex hydroclimatic patterns that varied over the last millennium. The records suggest a spatially divergent pattern across the region during the Medieval Climate Anomaly and the Little Ice Age. Southern peatlands were wetter during the Medieval Climate Anomaly, whilst northern and more continental sites were drier. There is no evidence at the multi-decadal sampling resolution of this study to indicate that Medieval mega-droughts recorded in the west and continental interior of North America extended to these peatlands in the north-east of the continent. Reconstructed Little Ice Age hydroclimate change was spatially variable rather than displaying a clear directional shift or latitudinal trends, which may relate to local temporary permafrost aggradation in northern sites, and reconstructed characteristics of some dry periods during the Little Ice Age are comparable with those reconstructed during the Medieval Climate Anomaly. The spatial hydroclimatic trends identified here suggest that over the last millennium, peatland moisture balance in north-eastern North America has been influenced by changes in the Polar Jet Stream, storm activities and sea surface temperatures in the North Atlantic as well as internal peatland dynamics

Crystal Structure of the Carbohydrate Recognition Domain of the Human Macrophage Galactose C-Type Lectin Bound to GalNAc and the Tumor-Associated Tn Antigen

12/IA/1398 16/IA/4419 GOIPG/2016/858 IF/00780/2015 PTDC/BIA-MIB/31028/2017 UIDB/04378/2020 PD/BD/142847/2018 RTI2018-094751-B-C22 RTI2018-099592-B-C2.The human macrophage galactose lectin (MGL) is an endocytic type II transmembrane receptor expressed on immature monocyte-derived dendritic cells and activated macrophages and plays a role in modulating the immune system in response to infections and cancer. MGL contains an extracellular calcium-dependent (C-type) carbohydrate recognition domain (CRD) that specifically binds terminal N-acetylgalactosamine glycan residues such as the Tn and sialyl-Tn antigens found on tumor cells, as well as other N- and O-glycans displayed on certain viruses and parasites. Even though the glycan specificity of MGL is known and several binding glycoproteins have been identified, the molecular basis for substrate recognition has remained elusive due to the lack of high-resolution structures. Here we present crystal structures of the MGL CRD at near endosomal pH and in several complexes, which reveal details of the interactions with the natural ligand, GalNAc, the cancer-associated Tn-Ser antigen, and a synthetic GalNAc mimetic ligand. Like the asialoglycoprotein receptor, additional calcium atoms are present and contribute to stabilization of the MGL CRD fold. The structure provides the molecular basis for preferential binding of N-acetylgalactosamine over galactose and prompted the re-evaluation of the binding modes previously proposed in solution. Saturation transfer difference nuclear magnetic resonance data acquired using the MGL CRD and interpreted using the crystal structure indicate a single binding mode for GalNAc in solution. Models of MGL1 and MGL2, the mouse homologues of MGL, explain how these proteins might recognize LewisX and GalNAc, respectively.publishersversionpublishe