A nonparametric test for change in variability using a proxy record with an application to ENSO

Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 35 (2008): L19708, doi:10.1029/2008GL035400.A common problem in climate science is determining whether the pattern of variability in a particular process or variable has changed over time. When the modern observational record is short, this problem can be addressed by comparing its variability to that of an historical proxy record. In doing so, it is important to recognize that the statistical properties of the modern and proxy records are different. Here, a nonparametric test for a change in variability in this situation is described that accounts for this difference. The method is illustrated by testing for a change in ENSO variability using a record of an ENSO index over the period 1871–2007 and oxygen isotope records extracted from corals at Palmyra Island that cover four different periods spanning the past millennium. The results are mixed.Partial funding for this work was provided by NSF Grant DEB-0515639

Assessing the Diversity of Antarctic and New Zealand Arthropods through DNA Barcoding

Diversity is the foundation of all biological and ecological studies. Globally however, biodiversity is under threat from the varied and cumulative impacts of humans on the environment. It is thus necessary to continually develop tools that are able to assess diversity at the scales now required. DNA barcoding has become an increasingly common approach for species identification as it is efficient and can facilitate high throughput analyses without the routine need of taxonomic experts. This thesis examines the genetic diversity of invertebrate groups from Antarctica and New Zealand to gain an understanding of current baseline levels of variability and to facilitate their use as indicators of environmental change. The juvenile stages of Ephemeroptera (mayflies), Plecoptera (stoneflies) and Trichoptera (caddisflies) (EPT taxa) are key components of aquatic food webs and are frequently used as bioindicators of water quality. However, challenges in identifying juveniles to species levels are one factor limiting their more routine use. New Zealand has over 244 caddisfly species 106 species of stonefly and 50 mayfly species all of which are endemic. Here, my primary aim was to obtain COI sequence coverage for the New Zealand EPT taxa using expertly identified collections of adult specimens. A second aim was to examine levels of sequence diversity within taxa and to test the endemicity of the New Zealand fauna through comparison with international records. Thus far, 225 caddisfly BINs, 48 stonefly and 37 mayfly BINs have been generated. Average intraspecific divergences were between 1.2-1.4% for all three orders while average interspecific distances ranged from 24-32%. The designation of all New Zealand EPT species as endemic was supported with interspecific divergences generally above 13%. These data can facilitate the rapid and accurate assessment of larval specimens and can furthermore be used to facilitate research into the phylogenetic and phylogeographic patterns that have shaped the EPT fauna worldwide. I also examined mitochondrial DNA (COI) sequences for three Antarctic springtail (Collembola) species collected from sites in the vicinity, and to the north of, the Mackay Glacier (77oS) within the Ross Sea region. This area represents a transitional zone between two biogeographic regions (North and South Victoria Land). Here, I assessed levels of genetic variability within and among populations of the three putative springtail species. Each of the three recognised species had multiple highly divergent intraspecific populations (5-11.3% sequence divergence). Based on molecular clock estimates, these divergent lineages were likely to have been isolated for 3-5 million years, a time when the Western Antarctic Ice Sheet (WAIS) was thought to have completely collapsed. Given the current isolation of these genetically distinct populations, any future changes in species’ distributions can be easily tracked through the DNA barcoding of individual springtails across the Mackay Glacier ecotone. Collectively these two studies have established baseline levels of COI diversity for New Zealand and Antarctic invertebrates. Furthermore, they have revealed hidden (cryptic) diversity in both regions and presented opportunities to incorporate DNA barcoding into future studies of New Zealand aquatic and terrestrial Antarctic ecosystems

Rancang Bangun Alat Pemberi Makan Otomatis Dan Monitoring Pakan Ikan Gurami Berbasis NodeMCU ESP8266 v3

Pakan merupakan faktor penting yang mempengaruhi pertumbuhan ikan. Pakan dapat mempengaruhi panjang, berat, atau pertambahan volume ikan. Saat ini masih banyak peternak yang memberikan pakan ikan gurami secara manual. Hal ini tentunya mengurangi efisiensi jika peternak memiliki banyak tambak atau memiliki usaha sampingan seperti mengelola sawah atau kebun. Oleh karena itu penelitian ini bertujuan untuk membuat suatu sistem alat pakan ikan dimana alat pakan ikan dapat secara otomatis mengeluarkan pakan pada pukul 07.00 dan 16.00 yang terhubung ke smartphone melalui aplikasi blynk. Sensor load cell digunakan untuk mengetahui berat pakan ikan pada wadah pakan yang dapat dimonitoring secara real time melalui aplikasi blynk dan LCD 16x2. Aplikasi blynk juga dapat memberikan perintah secara manual kepada alat pakan ikan agar dapat bekerja sewaktu-waktu. Modul NodeMCU ESP8266 v3 digunakan sebagai mikrokontroler yang dapat terhubung dengan wi-fi. Sistem monitoring menggunakan aplikasi blynk melalui widget gauge dan widget superchat. Pakan dalam wadah penampung dapat terdeteksi oleh sensor load cell. Berdasarkan hasil pengujian, diperoleh rata-rata error pada load cell pada alat sebesar 1,77% dengan delay salama 1 detik antara blynk dengan motor servo dan motor DC untuk bekerja. Rata-rata pakan yang dapat dikeluarkan oleh sistem adalah 18,2 gram dengan jarak lontar pakan ke kolam sejauh 3 meter hingga 42 cm. Sistem ini juga dapat dioperasikan secara manual dengan memberi perintah pada blynk. Kata Kunci : NodeMCU ESP8266 V3, Blynk, load cell

Salinity intrusion in a modified river-estuary system: an integrated modeling framework for source-to-sea management

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Hoagland, P., Beet, A., Ralston, D., Parsons, G., Shirazi, Y., & Carr, E. Salinity intrusion in a modified river-estuary system: an integrated modeling framework for source-to-sea management. Frontiers in Marine Science, 7, (2020): 425, doi:10.3389/fmars.2020.00425.Along the US Atlantic and Gulf coasts, port authorities and governments have been competing for access to federal funds to deepen the channels and berths in each of the major estuary-based harbors, thereby facilitating access by larger containerships. Consistent with a source-to-sea conceptualization, physical modifications of an estuary can result in dynamic changes to its water and sediment flows, resulting in new arrangements of environmental features. These modifications, in turn, can lead to redistributions of the net benefits arising from extant flows of valued ecosystem services to stakeholders and communities in the broader river-estuary system. Here, some of the implications of channel deepening in the Hudson river-estuary system were examined as a case study. An integrated analytical framework was developed, comprising hydrodynamic models of water flows and environmental characteristics, especially salinity; extreme value estimates of the occurrence of regional droughts; and assessments of the welfare effects of changes in ecosystem services. Connections were found among channel deepening in the lower estuary, increased risks to fluvial drinking water withdrawals in the upper estuary, and expected economic losses to hydropower generation in the upper river. The results argue for a more inclusive consideration of the consequences of human modifications of river-estuary systems.This work was sponsored by NSF Coastal SEES Grant No. 1325136

The human health effects of Florida Red Tide (FRT) blooms : an expanded analysis

Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Environment International 68 (2014): 144-153, doi:10.1016/j.envint.2014.03.016.Human respiratory and digestive illnesses can be caused by exposures to brevetoxins from blooms of the marine alga Karenia brevis, also known as Florida red tide (FRT). K. brevis requires macro-nutrients to grow; although the sources of these nutrients have not been resolved completely, they are thought to originate both naturally and anthropogenically. The latter sources comprise atmospheric depositions, industrial effluents, land runoffs, or submerged groundwater discharges. To date, there has been only limited research on the extent of human health risks and economic impacts due to FRT. We hypothesized that FRT blooms were associated with increases in the numbers of emergency room visits and hospital inpatient admissions for both respiratory and digestive illnesses. We sought to estimate these relationships and to calculate the costs of associated adverse health impacts. We developed environmental exposure-response models to test the effects of FRT blooms on human health, using data from diverse sources. We estimated the FRT bloom-associated illness costs, using extant data and parameters from the literature. When controlling for resident population, a proxy for tourism, and seasonal and annual effects, we found that increases in respiratory and digestive illnesses can be explained by FRT blooms. Specifically, FRT blooms were associated with human health and economic effects in older cohorts (≥ 55 years of age) in six southwest Florida counties. Annual costs of illness ranged from $60,000 to$700,000 annually, but these costs could exceed $1.0 million per year for severe, long-lasting FRT blooms, such as the one that occurred during 2005. Assuming that the average annual illness costs of FRT blooms persist into the future, using a discount rate of 3$2-24 million.This research was sponsored by the National Science Foundation under NSF/CNH Grant No. 1009106.L.E. Fleming acknowledges support from the European Regional Development Fund and the European Social Fund Convergence Programme for Cornwall and the Isles of Scilly

Variable Frame-Rate Speech Coding by Adaptive-Flux Interpolation

Variable frame-rate (VFR) speech coders have many desirable properties but make implicit assumptions concerning the nature of the spectral evolution of speech (Peeling and Pointing 1989). To date, these assumptions have been crude and unable to model speech parameters during extended periods of coarticulation. In particular they have been unable to cope with steadily changing formats. Thus, existing VFR methods must transmit many more frames than are really necessary. This paper presents a new technique; Adaptive-Flux Interpolation (AFI), which significantly extends the period over which accurate estimation can be performed and is much more robust and accurate than other methods

Multi-Dimensional Coding of Speech Data

This paper presents specific new techniques for coding of speech representations and a new general approach to coding for compression, which directly utilises the multi-dimensional nature of the input data. Many methods of speech analysis yield a two-dimensional pattern, with time as one of the dimensions. Various such speech representations and power spectrum sequences in particular, are shown here to be amenable to two-dimensional compression using specific models which take account of a large part of their structure in both dimensions. Newly developed techniques, namely, Multi-step Adaptive Flux Interpolation ( MAFI) and Multi-step Flow Based Prediction (MFBP) are presented. These are able to code power spectral density (PSD) sequences of speech more completely and accurately than conventional methods and at a low computational cost. This is due to their ability to model non-stationary, piecewise-continuous, signals, of which speech is a good example. MAFI and MFBP are first applied in the time domain and then to the encoded data in the second dimension. This approach allows the coding algorithm to exploit redundancy in both dimensions, giving a significant movement in the overall compression ratio. Furthermore, the compression may be reapplied several times. The data is further compressed with each application

Image Coding by Multi-Step, Adaptive Flux Interpolation

This paper describes and discusses a new technique, the multi-step adaptive flux interpolation (MAFI) and its application to image data for coding. The output of MAFI, when applied to an image, is still in an image form but has a more uniform feature density. This is because the original image has been warped by removing those rows and columns which contain mostly redundant pixels. It is also greatly reduced in size and the side information is minimal. The MAFI output can be further compressed using conventional coders, making its compression ratio even higher. Because of its warped nature, the MAFI output's statistics are also more consistent with the properties assumed by block-based discrete cosine transform (DCT) models