Concavity of the Mutual Information Rate for Input-Restricted Memoryless Channels at High SNR ∗

areas are analysis and combinatorics, with an emphasis on their applications to coding and information theory

Future of the Sea: Ocean Acidification

Ocean acidification (OA) and climate change are both influenced by increasing carbon dioxide concentrations coming from the atmosphere. However, the distinction between OA and climate change, is that OA is an alteration of the chemistry of seawater, therefore not a direct climatic process. The ocean is the largest natural reservoir of dissolved carbon and holds an immense buffering capacity for changes in atmospheric CO2 concentrations. The rapid increase of atmospheric CO2 since the industrial revolution has caused oceans and seas to absorb increasingly greater amounts of CO2. This process disturbs the pre-existing chemical equilibrium of the sea, resulting in seas changing their chemical state and altering the ocean pH. Ocean acidification has become one of the most studied topics in the last 10 years (Williamson et al. 2017; Browman 2016). The UK has made a significant contribution in understanding OA effects on biodiversity and biogeochemistry, and the socioecological impacts across species and ecosystems. The evidence suggests that OA will act differently across species with some impacts already occurring for sensitive marine species and with direct and indirect repercussions for ecosystems. The direct effects will include changes in species morphology, ecology and behaviour whilst indirect effects may be repercussions for processes or higher trophic groups (e.g. wider food web effects and interactions within and between species). This review summarises the available ‘state of the art’ information with regards to OA effects, current issues and further recommendations for consideration on what will be the likely future issues for OA. This information intends to support marine planning decisions and future policy adaptations. A detailed section is included on how these changes will affect UK interests (e.g. maritime industries, fishing, health and wellbeing). A summary of key highlights is outlined below. Monitoring data conducted over the North Sea assessments have shown clear pH changes in shelf and coastal sites. Trends of pH variability are still uncertain, and further work to disentangle the observed variability does require additonal investigation. Ocean Acidification 5 By 2100, under medium emissions scenarios, ocean pH is projected to decrease by 0.3 pH units from levels 100 years ago. Evidence suggests that similar trends in acidification during the Paleocene-Eocene Thermal Maximum (PETM) (around 56 million years ago), where the rate of release of CO2 was estimated to have been around one-tenth of current rate of anthropogenic emissions, caused the extinction of many seafloor organisms. Though the future impacts of OA on commercial fisheries are still uncertain, recent research has indicated that annual economic losses in the UK resulting from the effects of OA could reach US $97.1 million (GBP £7.47 million) by 2100. The integrity of some UK species and habitats of conservation importance (included under the current Marine Protected Areas – MPAs – designation) could be affected by future changes in pH and temperature. Ocean acidification research has demonstrated that some species may be more susceptible to changes in pH. These results are particularly important for UK shellfisheries and shellfish aquaculture, as these industries could be negatively affected

Dynamic Interactions among Boundaries and the Expansion of Sustainable Aquaculture

Aquaculture is the fastest growing food production system in the world, generating more than half of the global seafood harvested today. These type of activities are crucial to provide key nutritional components for humanity in the future as populations worldwide are increasing and the demands for securing food resources are imperative. Multiple socio-ecological factors such as weak regulations and focus on maximizing production limit production and threaten the sustainable growth of aquaculture. We present a novel policy framework to evaluate and pursue growth in aquaculture considering four boundaries: biological productivity, environmental constraints to that productivity, policy that inhibits or promotes different kinds of aquaculture, and social preferences that determine aquaculture markets. Using a range of scenarios, we have shown that sustainable growth in aquaculture requires simultaneous consideration of all four boundaries and the potential interactions between all of these options. Our proposed conceptual framework shows that to further expand the boundaries of aquaculture production, the policy focus must remain flexible to enable the adaptation of from single-boundary approaches. Our approach takes account of the current boundaries, helping to consider the adaptive policy, which is deemed as a necessary tool for considering the dynamic interactions among boundaries, thus addressing the problem of defining the evolving limits of sustainable aquaculture

Characterizations of how species mediate ecosystem properties require more comprehensive functional effect descriptors

The importance of individual species in mediating ecosystem process and functioning is generally accepted, but categorical descriptors that summarize species-specific contributions to ecosystems tend to reference a limited number of biological traits and underestimate the importance of how organisms interact with their environment. Here, we show how three functionally contrasting sediment-dwelling marine invertebrates affect fluid and particle transport - important processes in mediating nutrient cycling - and use high-resolution reconstructions of burrow geometry to determine the extent and nature of biogenic modification. We find that individual functional effect descriptors fall short of being able to adequately characterize how species mediate the stocks and flows of important ecosystem properties and that, in contrary to common practice and understanding, they are not substitutable with one another because they emphasize different aspects of species activity and behavior. When information derived from these metrics is combined with knowledge of how species behave and modify their environment, however, detailed mechanistic information emerges that increases the likelihood that a species functional standing will be appropriately summarized. Our study provides evidence that more comprehensive functional effect descriptors are required if they are to be of value to those tasked with projecting how altered biodiversity will influence future ecosystems

Prey items of Southern Fiscal Lanius collaris in southern Namibia

Although Southern Fiscals Lanius collaris are a common species in southern Namibia, we found only 18 impalements of prey items. We discuss these in relation to the species impaled, the site of impalement, the height above ground and the time of the year. We suggest that the small number of observations was due to the fact that the study period (July 2017 to June 2022) had below average rainfall, that food was therefore scarce and consumed, and that impalements events were rare

White-fronted Bee-eater Merops bullockoides increasing its presence along the Orange River in southern Namibia

The White-fronted Bee-eater Merops bullockoides is common in northeastern Namibia, in the Caprivi Strip. This paper reports the first records for southern Namibia, along the Orange River. The first record was made in 2010, in southeastern Namibia. By 2023, they were observed in small groups on seven out of 12 days on a canoe trip downstream of the 2010 sighting, as far west as Senderlingsdrift

Rising CO2 enhances hypoxia tolerance in a marine fish (article)

This is the final version. Available on open access from Nature Research via the DOI in this recordThe dataset associated with this article is available in ORE at https://doi.org/10.24378/exe.1523Global environmental change is increasing hypoxia in aquatic ecosystems. During hypoxic events, bacterial respiration causes an increase in carbon dioxide (CO2) while oxygen (O2) declines. This is rarely accounted for when assessing hypoxia tolerances of aquatic organisms. We investigated the impact of environmentally realistic increases in CO2 on responses to hypoxia in European sea bass (Dicentrarchus labrax). We conducted a critical oxygen (O2crit) test, a common measure of hypoxia tolerance, using two treatments in which O2 levels were reduced with constant ambient CO2 levels (~530 µatm), or with reciprocal increases in CO2 (rising to ~2,500 µatm). We also assessed blood acid-base chemistry and haemoglobin-O2 binding affinity of sea bass in hypoxic conditions with ambient (~650 μatm) or raised CO2 (~1770 μatm) levels. Sea bass exhibited greater hypoxia tolerance (~20% reduced O2crit), associated with increased haemoglobin-O2 affinity (~32% fall in P50) of red blood cells, when exposed to reciprocal changes in O2 and CO2. This indicates that rising CO2 which accompanies environmental hypoxia facilitates increased O2 uptake by the blood in low O2 conditions, enhancing hypoxia tolerance. We recommend that when impacts of hypoxia on aquatic organisms are assessed, due consideration is given to associated environmental increases in CO2.Natural Environment Research Council (NERC)Centre of Fisheries and Aquaculture Science (Cefas)Biotechnology and Biological Sciences Research Council (BBSRC

Multivariate tool condition monitoring in a metal cutting operation using neural networks

A thesis submitted in partial fulfilment of the requirements of the University of Wolverhampton for the degree of Doctor of PhilosophyThis thesis gives an account of an investigative study to develop a modular Tool Condition Monitoring System (TCMS) for metal cutting operations (turning in particular) through the application of multivariate process parameters and perceptron neural networks. The initial phase of the work was concerned with a literature survey that was conducted to investigate the extent of applicability of neural networks to TCMS to-date. The survey showed that in spite of well over a decade of research in this direction, a truly universally applicable TCMS has not yet been developed. A test bed to generate cutting data using a simple centred lathe onto which were attached the necessary sensors (a triaxial accelerometer and a triaxial dynamometer) was set-up. The instrumentation for the test bed comprised a personal computer fitted with a data acquisition card and connected to various peripheral signal conditioning instruments. After validating the test rig against an existing result set, a number of limited cutting test cuts were carried out to assess the impact of cutting conditions on signal behaviour for both worn and sharp plane-faced tool inserts. The acquired cutting data was used to assess the ability of a neural network in tool wear diagnosis. The application of a linear neural network model in the form of a Single Layer Perceptron (SLP) could not satisfactorily classify the cutting data into the two tool state classes desired. The non-linear nature of the cutting data led to the application of Multi-Layer Perceptron (MLP) networks that were better at handling such non-linearity. However, when the MLP neural network was trained and tested on cutting data, the nature of the results lead to the conclusion that changes in chip form during machining resulted in false alarms. The propensity for such false alarms was reduced by using tool inserts with controlled tool-chip contact (i.e. chip breaker geometry). The success of an initial system utilising flank wear only as the tool wear indicator to effect classification was extended. Nose wear and flank wear were used together but limiting the desired tool states to worn and sharp. This was further extended to include part worn, chipped and/or fractured tools. Finally, the developed model's range of application in a turning process was performed and its ability to recognise and distinguish tool wear from changes in the cutting conditions assessed. Though the developed modular TCMS model was capable of reasonable tool wear classification, it was incapable of detecting changes in the cutting conditions (particularly a reduction or an increase in the area of cut). A different classifier was developed to be used in parallel with the TCMS model in order for the system to be applicable over a broad range of cutting conditions

Primary omental torsion in children: case report

Primary omental torsion is a rare cause of acute abdominal pain, we report a case of 10-year-old boy admitted with crampy abdominal pain, routine laboratory tests and plain abdominal radiography was normal, the patient underwent surgical exploration with the initial diagnosis of appendicitis, primary omental torsion was confirmed and the omentum was untwisted, with good postoperative evolution.Pan African Medical Journal 2013; 14:5

KEJADIAN INFEKSI CACING SALURAN PENCERNAAN BABI YANG DIPOTONG DI RUMAH POTONG HEWAN PEGIRIAN KOTAMADYA SURABAYA

Penelitian ini bertujuan untuk mengetahui pengaruh jenis kelamin. asal hewan terhadap tingkat infeksi eaeing dan jenis eaeing pada saluran peneernaan babi yang dipotong di Rumah potong Hewan Pegirian Kotamadya Surabaya. Sejumlah 60 ekor babi dibagi dalam dua kelompok yang masing-masing terdiri dari 30 sampel berdasarkan jenis kelamin dan 30 $ampel berdasarkan daerah asal hewan. Untuk pengujian hipotesa digunakan UJl Chi Kwadrat sedangkan untuk mengidentifikasi telur eaeing pada sampel dari tinja babi digunakan pemeriksaan natif. pengendapan dan pengapungan. Untuk mengetahui jumlah telur eaeing per gram tinja (TCGT) digunakan metoda Me Master yang dimodifikasi. Hasil penelitian menunjukkan bahwa jenis kelamin dan asal hewan (Madiun dan Tulungagung) tidak berpengaruh terhadap kejadian infeksi eaeing saluran peneernaan. Jenis telur eaeing yang ditemukan adalah Asca.ris suum. Oe$ophagustomt.lffi dentatum, Paragon.imt.!s sPP., Stephant.!r<..IS dentatt.ls dan Trichuris sui.!:;