Satellite Telemetry of Tidal Data in the Hydrographic Service of the Royal Australian Navy

The Hydrographic Service of the Royal Australian Navy (RAN) is responsible for charting of the area extending from the middle of Indian Ocean to the equatorial waters of Papua New Guinea to the Antarctic, with tidal regimes varying from fully diumal to fully semi-diurnal and from less than lm to over 12m. Accurate tidal information is vital in surveying and charting, and to provide it, three years ago, Hydrographic Service RAN with assistance from InterOcean developed the then largest network of unattended INMARSAT-C telemetry units in the world by using an array of digital tide gauges linked to the INMARSAT-C satellite telemetry by a remote data acquisition system. This application of modern technology was a major step from the previous practice of manned tide camps. During the last three years, the equipment has been further improved and modified to rectify minor problems encountered during that period. In general, the introduction of modern technology to tidal data acquisition and telemetry has been a success for the RAN hydrographers. Tide gauges, telemetry equipment and ancillary gear have proved their value, giving reliable service with low maintenance and operational costs

Time Varying Objects in ECDIS Today, tomorrow and soon after

ECDIS is about to become a commercial reality. However, the full potential of the system is not likely to be realised until Time Varying Objects (TVOs) like tides, currents etc., are incorporated to represent the constantly changing conditions that meet the navigators every day. The relevant standards need to be urgently developed to prevent uncoordinated development of incompatible systems. A coordination of the efforts of several Working Groups of IHO is required to provide a viable solution

Heat Stress Vulnerability: Analyzing the Socio-Environmental Factors Influencing Heat Stress Hospital Visits and Implementation of Green Infrastructure in New York City

The goal of this study was to identify factors leading to heat stress hospitalizations visits in New York City through the use of climatological and social science data, thus enabling greater targeting of individuals and groups with heightened vulnerability to extreme heat. Recent research has established that climate change will increase overall temperatures in New York City in the future. Heat waves are predicted to increase in frequency and severity, adversely impacting public health and increasing heat vulnerability that could lead to heat stroke or other comorbidities. This dissertation takes into account existing data to generate a new model that seeks to answer the following fundamental research question: How do social vulnerability and environmental risk factors independently impact heat stress hospitalization visits in New York City? In order to address this question I created and tested the efficacy of a new regression model called the Heat Multiplicative Model (HMM) technique using NYC as a case study. The primary contribution of this model is the combined use of temperature data derived from two sources: space-based remotely-sensed moderate-resolution land data from Landsat satellite imagery and ambient temperature data from ground sensors, both of which are multiplied by social and environmental factors to develop new weighted factors that may be useful for public health research. HAM with the three variables (including Landsat) emerged as the better model because the components of the regression exhibited the correct variable interactions and were statistically significant. In conclusion, it appears there might be some slight value to utilizing two temperature variables within the regression to improve the R-square

Digital Tide Tables: A Necessity for Navigation in the Electronic Age

Tide Tables, produced by the relevant Hydrographic Offices, are a mandatory complement to navigational charts for any vessel sailing in tidal waters, i.e. in all the world's oceans and almost all of its seas. Until recently, they were almost exclusively in a printed form. However, the arrival and widespread use of personal computers is changing the status quo. Several digital tidal prediction programs of varying accuracy have appeared on the market, and Hydrographic Offices are being pressured to move into the electronic world as well. To date, only a few countries produce digital versions of authorized Tide Tables, with various levels of sophistication. The introduction of the Electronic Chart Display and Information System (ECDIS) is now emphasizing the need for digital tidal data, with more Hydrographic Offices expected to comply. Those mariners using electronic navigational charts now require digital tidal predictions as a companion to the digital ECDIS.Graphical representation of traditionally numeric tidal data is now practically "de rigueur" for Digital Tide Tables. With predictions for many secondary ports available with accuracy comparable to standard ports, the whole concept of "secondary" ports is challenged. Early versions of Digital Tide Tables had, at best, a relatively simple user menu with a listing of ports for which predictions were available. This is also changing, as Australia has already introduced a master geographical interface, showing the locations of available ports via several larger scale index charts.The second generation of Digital Tide Tables will include a "seamless" incorporation in the ECDIS to provide authorized (i.e. legal) tidal predictions on demand for real-time navigation. It is anticipated that the ECDIS community will enhance this further with spatial overlays and access to shore-based modelling of tidal heights and streams, as well as real-time water level measurements, where available

Drifting inwards in protoplanetary discs I Sticking of chondritic dust at increasing temperatures

Sticking properties rule the early phases of pebble growth in protoplanetary discs in which grains regularly travel from cold, water-rich regions to the warm inner part. This drift affects composition, grain size, morphology, and water content as grains experience ever higher temperatures. In this study we tempered chondritic dust under vacuum up to 1400 K. Afterwards, we measured the splitting tensile strength of millimetre-sized dust aggregates. The deduced effective surface energy starts out as $\gamma_e = 0.07\,\rm J/m^2$. This value is dominated by abundant iron-oxides as measured by M\"ossbauer spectroscopy. Up to 1250 K, $\gamma_e$ continuously decreases by up to a factor five. Olivines dominate at higher temperature. Beyond 1300 K dust grains significantly grow in size. The $\gamma_e$ no longer decreases but the large grain size restricts the capability of growing aggregates. Beyond 1400 K aggregation is no longer possible. Overall, under the conditions probed, the stability of dust pebbles would decrease towards the star. In view of a minimum aggregate size required to trigger drag instabilities it becomes increasingly harder to seed planetesimal formation closer to a star

Syringomyelia associated with cervical spondylotic myelopathy causing canal stenosis. A rare association

Background Although cervical spondylosis is extremely common, only few cases with associated syrinx have been reported. Depending on review of two large data bases, we report this case series. In addition, we evaluated the posterior decompression as the management option in treatment of this rare condition. Materials and methods Data of all cases with cervical spondylosis and canal stenosis that sought medical advice or needed decompressive laminectomy/laminoplasty between the years 2006 and 2015 were checked in manually. Perioperative data, together with follow up were reviewed. Results Out of five cases found in the reviewed data; four cases undergone posterior decompression (laminectomy in two cases and laminoplasty in the other). One case refused surgery. Along mean follow up period of 6.25 months; three cases improved markedly, while in one case no improvement occurred. Conclusion Cervical spondylotic myelopathy can rarely cause syringomyelia. Posterior decompression would be the preferable management option with clinical improvement of most of the cases

Evaluation of large language models for discovery of gene set function

Gene set analysis is a mainstay of functional genomics, but it relies on manually curated databases of gene functions that are incomplete and unaware of biological context. Here we evaluate the ability of OpenAI's GPT-4, a Large Language Model (LLM), to develop hypotheses about common gene functions from its embedded biomedical knowledge. We created a GPT-4 pipeline to label gene sets with names that summarize their consensus functions, substantiated by analysis text and citations. Benchmarking against named gene sets in the Gene Ontology, GPT-4 generated very similar names in 50% of cases, while in most remaining cases it recovered the name of a more general concept. In gene sets discovered in 'omics data, GPT-4 names were more informative than gene set enrichment, with supporting statements and citations that largely verified in human review. The ability to rapidly synthesize common gene functions positions LLMs as valuable functional genomics assistants

Peak Electric Load Relief in Northern Manhattan: An Exploratory Data Analysis

The aphorism “Think globally, act locally,” attributed to René Dubos, reflects the vision that the solution to global environmental problems must begin with efforts within our communities. PlaNYC 2030, the New York City sustainability plan, is the starting point for this study. Results include (a) a case study based on the City College of New York (CCNY) energy audit, in which we model the impacts of green roofs on campus energy demand and (b) a case study of energy use at the neighborhood scale. We find that reducing the urban heat island effect can reduce building cooling requirements, peak electricity loads stress on the local electricity grid and improve urban livability

Missing elimination via membrane vesicle shedding contributes to the diminished calcium sensitivity of listeriolysin O

The lytic capacity of cholesterol-dependent cytolysins is enhanced in the extracellular calcium-free environment through a combination of limited membrane repair and diminished membrane toxin removal. For a typical neurotoxin of the group, pneumolysin, this effect has already been observed at reduced (1 mM) calcium conditions, which are pathophysiologically relevant. Here, we tested another neurotoxin of the group, listeriolysin O from L. monocytogenes, active in the primary vacuole after bacterium phagocytosis in host cells. Reduced calcium did not increase the lytic capacity of listeriolysin (in contrast to pneumolysin), while calcium-free conditions elevated it 2.5 times compared to 10 times for pneumolysin (at equivalent hemolytic capacities). To clarify these differences, we analyzed membrane vesicle shedding, known to be a calcium-dependent process for toxin removal from eukaryotic cell membranes. Both pneumolysin and listeriolysin initiated vesicle shedding, which was completely blocked by the lack of extracellular calcium. Lack of calcium, however, elevated the toxin load per a cell only for pneumolysin and not for listeriolysin. This result indicates that vesicle shedding does not play a role in the membrane removal of listeriolysin and outlines a major difference between it and other members of the CDC group. Furthermore, it provides new tools for studying membrane vesicle shedding

Listeriolysin O Causes ENaC Dysfunction in Human Airway Epithelial Cells.

Pulmonary permeability edema is characterized by reduced alveolar Na⁺ uptake capacity and capillary barrier dysfunction and is a potentially lethal complication of listeriosis. Apical Na⁺ uptake is mainly mediated by the epithelial sodium channel (ENaC) and initiates alveolar liquid clearance. Here we examine how listeriolysin O (LLO), the pore-forming toxin of Listeria monocytogenes, impairs the expression and activity of ENaC. To that purpose, we studied how sub-lytic concentrations of LLO affect negative and positive regulators of ENaC expression in the H441 airway epithelial cell line. LLO reduced expression of the crucial ENaC-α subunit in H441 cells within 2 h and this was preceded by activation of PKC-α, a negative regulator of the channel\u27s expression. At later time points, LLO caused a significant reduction in the phosphorylation of Sgk-1 at residue T256 and of Akt-1 at residue S473, both of which are required for full activation of ENaC. The TNF-derived TIP peptide prevented LLO-mediated PKC-α activation and restored phospho-Sgk-1-T256. The TIP peptide also counteracted the observed LLO-induced decrease in amiloride-sensitive Na⁺ current and ENaC-α expression in H441 cells. Intratracheally instilled LLO caused profound pulmonary edema formation in mice, an effect that was prevented by the TIP peptide; thus indicating the therapeutic potential of the peptide for the treatment of pore-forming toxin-associated permeability edema