Fluctuations In Ratios Research Articles

Developing practical models for predicting chlorophyll levels in the Andong Reservoir using empirical and machine learning approaches based on integrated analysis of physical, chemical, and hydrological indicators

Managing excessive phytoplankton biomass is a pressing issue worldwide and requires precise predictions and efficient water quality control. In this study, we employed the random forest approach to build a practical predictive model for phytoplankton biomass as determined by chlorophyll (CHL-a) levels. Using an integrative 15-year dataset, we obtained insights into CHL-a dynamics and identified important factors influencing it. Seasonal dynamics were crucial for shaping water quality, with meteorological and hydrological fluctuations playing pivotal roles. Elevated suspended solids and phosphorus levels during the summer monsoon indicated increased runoff and nutrient loading, contributing to fluctuations in nutrient ratios. CHL-a was also responsive to seasonal variations in nutrient availability, particularly in phosphorus and ammonium-nitrogen (NH4-N). These results suggest the importance of nutrient management strategies for controlling and mitigating eutrophication risk. The random forest model had practical accuracy (R2 = 0.66, RMSE = 1.85) for predicting long-term CHL-a variation and identified phosphate-phosphorus, water temperature, and NH4-N as the most important predictors. However, our findings emphasize the importance of comprehensive analyses to identify the factors driving CHL-a variation. Combining the strengths of machine learning with multifaceted insights would enhance prediction accuracy and efficiency, ultimately facilitating informed decision-making for reservoir management and environmental conservation efforts.

ANALSIS KOMPARASI KINERJA KEUANGAN BANK MEGA SYARIAH MENGGUNAKAN METODE RGEC PADA MASA SEBELUM DAN SELAMA PANDEMI COVID-19

The COVID-19 pandemic has had an impact on all industrial sectors in Indonesia, one of which is the sharia banking sector. During the pandemic, banking performance experienced fluctuations in terms of deposits and debt financing; Bank Mega Syariah also experienced fluctuations in financial ratios and deposits, which could have an impact on the bank's financial performance. The purpose of this study is to evaluate Bank Mega Syariah's financial results utilizing the RGEC approach both before and after the COVID-19 epidemic. This study used quantitative research using a descriptive methodology. Data was acquired through the use of documentation methods. Financial ratio analysis utilizing the RGEC method is the data analysis method employed. The findings demonstrate that Bank Mega Syariah's financial performance, as measured by the RGEC technique, was superior to its pre-COVID-19 pandemic financial performance during the pandemic-affected period. This is shown by Bank Mega Syariah's ability to continue turning in a profit despite the COVID-19 pandemic's negative impact on the business environment. This accomplishment is demonstrated by the growth in several key business metrics, which were maintained, including bank profitability, finance distribution, and Third Party Funds.Keywords: Financial Performance; Bank Health Level; RGEC Method

Analisis Kinerja Keuangan pada Koperasi Usaha Warga Pupuk Kujang Periode 2018-2022

This research analyzes the financial performance of the Koperasi Usaha Warga Pupuk Kujang Cikampek during 2018–2022, focusing on financial ratios such as liquidity, solvency, profitability, and activity. Using a quantitative descriptive approach, the study employs annual financial data to identify trends and factors influencing performance. Findings reveal significant fluctuations in the cooperative's financial ratios over the examined period. While liquidity ratios fluctuate, solvency ratios show improvement over time, indicating efficient debt management and asset utilization. However, profitability ratios exhibit a declining trend, emphasizing the need for measures to enhance revenue generation and cost management. Meanwhile, activity ratios depict gradual improvement, indicating enhanced operational efficiency. The implications suggest the importance of careful monitoring, risk management, and strategic initiatives to ensure sustainable growth and financial stability for Koperasi Usaha Warga Pupuk Kujang Cikampek.

Economic and exergy transmission analysis of the gas-liquid type compressed CO2 energy storage system

Exergy transmission characteristic of the compressed CO2 energy storage system is significant to evaluate the system performance while little attention has been paid to this analytical method in the literature. A CO2 energy storage cycle configured with a gas holder as a low-pressure gas reservoir and a liquid tank as a high-pressure gas reservoir is studied comprehensively. The exergy transmission characteristics and the cost uncertain analysis are considered. Results demonstrated that the round trip efficiency and levelized cost of storage are 71.2 % and 0.1286 $/kWh under optimal design parameters, respectively. Keeping the charge/discharge duration ratio close to 1 has a positive effect on optimizing the economic performance of the system. With the general exergy model of the whole system configured for the charge and discharge process, the study uncovers the fluctuations in the pertinent proportional ratios and exergy transfer efficiency in relation to important parameters. Except for the turbomachinery isentropic efficiency, which impacts nearly all efficiencies, the variation of each parameter only governs the modification of the exergy transfer efficiency for a specific term or a pair of terms. Furthermore, the thermal exergy efficiency of the discharge process and intercooler has a maximum value as the cold-side temperature difference of the high-temperature cooler changes to 27 °C.

A STUDY ON WORKING CAPITAL MANAGEMENT AT ASHLEY ALTEAMS INDIA LIMITED

This study delves into the intricacies of operating capital management within Organization, analyzing the company's strategies and practices in keeping most suitable tiers of liquidity and operational performance. Through a comprehensive analysis of monetary statements, cash go with the flow patterns, and enterprise benchmarks, the studies evaluate the effectiveness of numerous running capital control techniques employed by way of Organization. Furthermore, the study explores the impact of powerful running capital control at the enterprise's profitability, cash go with the flow dynamics, and common economic performance. By providing treasured insights into the agency's control of cutting-edge assets and liabilities, this study contributes to the wider understanding of running capital control practices inside the context of contemporary business operations. This observe examines the fluctuations in economic ratios through the years and the general working capital management practices of Organization. Key words: Operating Capital Management, Liquidity Management, Profitability Analysis, Financial Performance

Reducing nutrient imbalance in recirculating drainage solution of stone wool grown tomato

Recirculation of drainage solution reduces the emission of water, nutrients and plant protection products from both substrate-based and water-based growing systems. During cultivation, deviations in nutrient ratios in the root environment may potentially affect yield and quality as well as motivate a grower to discharge the drainage solution. Our objective was to quantify imbalances in nutrient ratios and to assess what part of the nutrient imbalances can be prevented with practical measures. included daily balances for water and individual nutrients, using data from a commercial cherry-tomato grower. The balances showed plant water uptake and uptake of individual nutrients were not strictly correlated. It was also possible to establish individual relations between solar radiation sum and water uptake as well as uptake per individual nutrient. After 200 days of production, an adapted balance was prepared and then used as a model. This model was used to compare various nutrient supply strategies to reduce daily fluctuations in nutrient ratios. Simulations showed the imbalances between supply and uptake could be halved compared with the original grower strategy. This was realized by using a combination of drainage volume percentage, the supply EC and the correlation of the supplied solution EC with solar radiation forecast. The conclusion is that nutrient balances can deliver plant uptake data for water and individual nutrients, which can then be correlated with solar radiation. This can be used to identify and reduce deviations from targeted ratios between nutrients in the supplied solution as well as in the root solution. These conclusions take advantage of information available in practice.

Stable isotopic investigation of the feeding ecology of wild Bornean orangutans

AbstractObjectivesWe applied stable carbon and nitrogen isotope analyses to wild Bornean orangutans (Pongo pygmaeus morio) to investigate the feeding ecology of wild orangutans. Compared with African great ape species, orangutans are adapted to environments with chronic lower nutrition. But the usefulness of stable isotope analysis in the study of wild orangutan feeding ecology has not been fully explored.MethodsThe study site was a primary lowland dipterocarp forest in the Danum Valley, Sabah, Malaysia. A total of 164 plant and 94 fecal samples collected across 18 months were analyzed.ResultsCarbon and nitrogen stable isotope ratios of plant food samples do not systematically vary by plant parts (i.e., bark, fruits, and leaves). Elemental composition and stable isotope ratios of orangutan feces do not systematically vary by orangutans' sex and age classes, although fecal stable isotope ratios showed seasonal fluctuations. No isotopic contribution of breast milk was found in fecal samples collected from individuals at 2.7–6.5 years of age.ConclusionsThis study revealed key characteristics of the stable isotope ecology of wild orangutans living in a primary lowland forest. Although there was little isotopic variation among plant foods and orangutan individuals, seasonal fluctuations in baseline isotope ratios or orangutans' diet were found in Danum valley.

The eurozone: What is to be done to maintain macro and financial stability?

The financial stability of the eurozone depends on its macroeconomic stability and vice versa. We construct a macro DSGE model of the eurozone and its two main regions, the North and the South, with the aim of matching the macro facts of these economies by indirect inference and using the resulting empirically-based model to assess possible new policy regimes that could maintain financial stability. The model we have found to fit the facts suggests that substantial gains in stability and consumer welfare are possible if the fiscal authority in each region is given the freedom to respond to its own economic situation. Further gains could come with the restoration of monetary independence to the two regions, in effect creating a second ‘southern euro’ bloc. Enhanced fiscal flexibility increases fluctuations in debt and deficit ratios to GDP while keeping average ratios stable, maintaining solvency. A reformed Stability and Growth Pact could be limited to monitoring solvency.

A Simple Method for the Analysis of Fumarolic Gases Using Response-Adjusted Sensors with a UAV

Recent developments in unmanned aerial vehicle (UAV) technology have made it possible to measure gas compositions in volcanic plumes using lightweight compact gas sensors. However, the differences in the responses of each gas sensor can be critical in estimating gas compositions based on regression scatter plots, particularly for small plumes emitted during volcanic unrest and non-eruption periods. Based on the laboratory experiments, we show that air blowers easily adjust sensor responses and improve correlation on regression scatter plots, allowing quick composition estimates without the use of mathematical applications. Applying our measurement system, lightweight compact gas sensors for H2S, SO2, CO2, and H2O, with air blowers suspended from a UAV, were used to determine the compositions of a small plume at Io-yama, Kirishima volcano, Japan. The compositions of the plume estimated by our system were reasonably consistent with those obtained by laboratory analysis of volcanic gas collected at ground level near the vent, with fluctuations in CO2 ratios and lower H2O ratios, relative to other gases, being observed. For more accurate estimations of CO2 and H2O concentrations, low humidity conditions at a distance from the fumarole are preferable for analysis of plumes diluted by ambient dry air. Our measurement system is simple, easy to set up, and useful for estimating the compositions of small passive fumarolic gas plumes during volcanic unrest and non-eruption periods, without mathematical applications.

Functional Expense Allocation Ratios to Predict Financial Condition at Public Higher Education Institutions

The higher education industry has faced increased competition in recent years from new institutions and learning platforms entering the marketplace. Public higher education institutions, in particular, have been forced to develop strategic plans due to limited state funding in recent years. These colleges and universities face the challenge of allocating their limited financial resources in a manner that will optimize financial strength and ensure long-term sustainability. Institutions classify their operating expenses into several different functional expense categories, including instruction, academic support, student services and operations and maintenance of plant. This paper analyzed the relationship between allocation ratios of functional expenses and an institution’s financial condition. Multiple regression analysis was performed to determine how fluctuations in financial allocation ratios impact an institution’s financial condition. The research could aide higher education institutions in strategically allocating resources to improve their financial position.

Sedimentological and palynological assessment of three wells in eastern Dahomey Embayment, southwestern Nigeria, West Africa

Integrated studies were carried out on one hundred and eleven (111) ditch samples retrieved from three wells drilled in Lagos area within the Dahomey Embayment, coastal southwestern Nigeria. The purpose of this study is to determine the provenance, heavy mineral assemblage(s), establish the lowstand - highstand episodes, Quaternary palaeoenvironment and date the encountered lithofacies which constitute sandstones, siltstones with thin beds of lignite. The textural parameters show that the sandstones are medium to fine grained with the lignite consisting of plant fragment remains. Petrographic analyses showed abundant detrital minerals with average modal composition of quartz (Q = 90%), feldspar (F = 2%) and rock fragments (RF = 4%). The QFR ternary plots revealed that the sandstones are quartz arenites of continental block provenance origin deposited under humid climatic setting. This lithofacies has undergone medium distance range of transportation and have been subjected to mechanical and chemical weathering prior deposition. The heavy mineral assemblages and the ratios of Zircon-Tourmaline (ZTR index) in the wells suggest matured sediments. The Apatite: Tourmaline (ATi) ratios showed variations within the studied wells indicating differences in rate of weathering. It is evident that the periods of residence on the floodplain despite similar provenances and fluctuations in ratios, suggest sea level changes. The fluctuations in apatite: tourmaline ratios with respect to weathering are attributed to rapid changes in climatic conditions during the floodplain residence. The high ATi values in sandstone were deposited during relative sea level highstand (transgression), while sandstones with low ATi were deposited during lowstand (regression) in Nigeria and along the West African region. The abundance species of Rhizophora sp., Avicennia africana, Acrostichu mauruem, Laevigatosporite sp., Combretaceae sp., Mitrogynaciliata, Sapotaceae sp., Disopyros sp., Elaeis guineensis and Alchronea spp. indicated depositional transition from mangrove to fresh water swamp due to the episodic highstand and lowstand regimes. The abundance of Podocarpus milianjanus and Retitricolporites hians and the absence of Miocene diagnostic forms suggest late Pleistocene (Tarantian = 0.012–0.126 Ma) deposition.

Crystallomorphological and physical properties of apatite from carbonatites

This paper presents the results of the study of x-ray luminescence of apatite from different genetic types of apatite species in order to study its geochemical characteristics and the possibility of using as a mineral indicator the conditions of ore formation and for search purposes. Apatite Ca2Ca3(F,Cl,OH)2[PO4]3 contains impurities Gd3+, Ce3+, Eu2+, Dy3+, Sm3+, Nd3+ as well as Mn2+ and others. Syngony is hexagonal. Crystals of prismatic habit; usually ending in dipyramide or basopinacoid. Sometimes forms tabular crystals. A hexagonal prism is often preserved. Color greenish, bluish-green; pinkish-purple, gray; often white, colorless or brown. Quite often translucent due to the presence of small internal cracks and inclusions; sometimes the inclusions are arranged oriented, preferably parallel to the main axis of the crystal. Brightly luminesces in cathode, x-ray and ultraviolet rays. The intensity and color of luminescence varies widely depending on the impurities. The presence of three crystal chemical positions in the structure of apatite – two cationic and one anionic makes it possible to be realized in the mineral by a wide heterovalent substitution. The distribution of isomorphic impurities between the crystal chemical positions will depend on the type of cation, its amount, as well as anionic substitutions in apatite. To determine the luminescence intensity values of the characteristic isomorphic impurities of apatite TR3+ (Gd3+, Ce3+, Eu2+, Dy3+, Sm3+, Nd3+) and Mn2+, the X-ray luminescence method was applied. Apatites of different genetic types of the Aldan, Baltic Shields, the Baikal region (Russia), the Sette-Daban Range, and the Maimech-Kotui Province (Yakutia) and the Ukrainian Shield were investigated. The obtained values of luminescence intensity of TR3+ and Mn2+ can be used to diagnose the genetic type of apatite species, the conditions of mineral formation, the type of their mineralization and for search purposes. On the basis of factor analysis, it can be concluded that the intensity of the luminescence centers of rare earth elements in the apatites of each complex depends on the relative age position of the mineral in the groups of successively formed rocks. Analysis of apatite carbonatites from different deposits showed minimal fluctuations in the ratios of radiation intensity of X-ray centers (Ce3+, Sm3+, Mn2+, Eu2+), which may indicate a close geochemical situation and, consequently, the only source of matter in the formation of carbonates. Analysis of apatite carbonatites from different fields showed minimal fluctuations in the radiation intensity ratios of the centers of X-ray luminescence (Ce3+, Sm3+, Mn2+, Eu2+), which, in my opinion, may indicate a close geochemical situation and, as a consequence, the substance or the result.

Stable isotopic and geochemical analysis of lacustrine carbonates from the Al-Azraq basin, Jordan: implications for paleoenvironment and paleohydrology

This study tests the geochemical basis for the paleoenvironmental history of 31 m of cored lacustrine sediments in the Al-Azraq basin, in the eastern desert of Jordan. The analysis of carbon and oxygen isotopes of carbonates distinguishes patterns of aridity and increased moisture over greater than 250 ka. Initial analysis examined the isotope data identifying oxygen isotopes of carbonate that reflect precipitation and evaporation trends which are further supported by the paleoenvironmental proxies of ICP-AES, SEM, XRD, and magnetic susceptibility. The study identifies seven environmental zones that fluctuate between phases of aridity punctuated with periods of higher moisture and occasional aeolian deposition. The covariance of δ13Ccarb and δ18Ocarb indicates the paleolake was a closed-basin system throughout its history. Sediments from 31.69 m to the surface transition from lake to increasingly arid environments with multiple wet periods and the upper most sediments reflecting aeolian deposition determined by significant fluctuations in isotopes, grain size, and element ratios. Fe/Mn demonstrates a saw-toothed pattern for the first 10 m averaging below 100. The ratio then fluctuates substantially into the 200 and 300s in Zones F and G. The ratio of Sr/Ba averages 1.46 yet fluctuates strongly in arid zones of F and G, and to as much as 43.48 in Zone C. X-ray diffraction and SEM reveal the presence of carbonate minerals including authigenic calcite, dolomite, gypsum, and celestite in arid zones. Zones B and D signal higher moisture environments with negative δ18Ocarb values and increases in clay percent. IRSL determinations provide a sequence of three ages reaching saturation limits of greater than 250 ka at 10 m. The AZ1 lacustrine basin record has significantly older sediment ages than the fringing marsh and oasis sites. Correlation with speleothem records from local and northern Israel caves generally corresponds with MIS 9, MIS 8, and MIS 6. Correlation with the youngest age could be either MIS 5, a significant wet period recognized regionally and along the basin margins, or MIS 2, but neither are strong signals in the central basin.

Using empirical dynamic modeling to assess relationships between atmospheric trace gases and eukaryotic phytoplankton populations in coastal Southern California

Many different atmospheric trace gases have been directly and indirectly linked to biological sources and sinks. Here we assess how atmospheric mixing ratios of a range of halocarbons (CH3Br, CH2Br2, CHBr3, CH3Cl, CHCl3, and CH3I) and COS are causally connected to naturally occurring marine eukaryotic phytoplankton in coastal Southern California. We use a self-organizing map to characterize the abiotic environment and empirical dynamic modeling with convergent cross mapping to identify causal interactions between multiple in situ 8-year time-series, sampled at the Ellen Browning Scripps Pier at Scripps Institution of Oceanography. Our work supports previous findings that halocarbon production is found in a variety of marine phytoplankton taxa and suggests that local phytoplankton may have the ability to affect changes in the mixing ratios of halocarbons in nearshore environments. There were notable links between changes in CH3I and several different diatom taxa and between changes in CHCl3 and a group of phytoplankton during specific ecosystem states. Our results suggest that both seasonal and non-seasonal shifts in eukaryotic phytoplankton structure contribute to small fluctuations in atmospheric halocarbon mixing ratios that exhibit strong seasonality and may occasionally play a larger role in atmospheric mixing ratios of halocarbons that display reduced seasonality.

Effects of a transient marine sulfur reservoir on seawater δ18OSO4 during the Paleocene-Eocene Thermal Maximum

Recent work suggests that during the Paleocene-Eocene Thermal Maximum (PETM) the volume of the oceanic oxygen minimum zone (OMZ) has expanded by one order of magnitude and acted as a transient reservoir for reduced sulfur. Fluctuations in the seawater S-isotope ratios (δ34SSO4) can be used to estimate the size of this reservoir, but do not capture the gross fluxes associated with hydrogen sulfide reoxidation at the upper and lower boundaries of the OMZ. Isotope exchange processes during microbially mediated sulfate reduction as well as constant reoxidation of hydrogen sulfide to sulfate, however, affect the oxygen isotope ratio of seawater sulfate (δ18OSO4). Here we present a high-resolution (10-kyr) barite δ18OSO4 record. Our data shows that the δ18OSO4 value increased by 1.5‰ within 48 kyrs from the onset of the PETM and then returned to the pre-excursion value over the next 200 kyrs. Quantitative modeling suggests that the gross microbial sulfate reduction (MSR) flux was on the order of 4 × 1014 mol/yr, which is about one order of magnitude higher than the gross sulfate reduction flux in the modern ocean.

Can Simple Metaphors Be Used as Decision Aids to Promote Professional Skepticism?

ABSTRACTThis study examines the potential for metaphorical priming to promote professional skepticism. Results of an experiment with 99 senior auditors from two Big 4 audit firms indicate that reading metaphors that are entirely unrelated to audit evidence can promote professional skepticism and influence auditors' judgments. Relative to auditor participants who did not read a metaphor, participants who read a metaphor related to concerns about the honesty of the sources of information (client-skeptical metaphor) or concerns about one's own ability to detect problems (self-skeptical metaphor) assessed higher levels of fraud risk. These auditors also perceived that fraud-based explanations were more likely to cause fluctuations in client ratios. Importantly, metaphorical primes improved auditors' fraud-related actions and caused them to focus on issues that were the most likely explanations for the audit evidence. Results suggest that metaphorical priming may represent a powerful and efficient tool for promoting high-quality and professionally skeptical judgments.

High nutrient availability leads to weaker top‐down control of stream periphyton: Compensatory feeding in Ancylus fluviatilis

Abstract Benthic algal biomass and distribution in freshwater ecosystems are determined by both nutrient availability (bottom‐up control) and grazing activity by herbivores (top‐down control). Fluctuations in algal nutrient ratios may cause grazers to optimise their food intake through behavioural strategies in order to maintain a constant soft body stoichiometry. Such linkages between nutrient availability and grazing control of algal biomass are as yet poorly understood. In this study, we tested whether the stream‐dwelling freshwater gastropod Ancylus fluviatilis would increase its food consumption rate with decreasing periphyton nutrient content, a behaviour known as compensatory feeding. We performed a fully factorial microcosm experiment in which two levels of periphyton phosphorus content (low versus high) were crossed with grazer presence/absence in 12 circular flumes. After 1 week of grazing, food consumption rates were measured by determining the periphyton difference between grazed and ungrazed flumes, and the periphyton biomass variability in every flume was described with a coefficient of variation. The food consumption rate of A. fluviatilis was significantly higher in the low phosphorus compared to the high phosphorus treatment, supporting the compensatory feeding hypothesis. As a result, in the presence of grazers, periphyton biomass was significantly lower under low phosphorus availability, while biomass was not affected by nutrient enrichment in the grazer‐free flumes. Despite the strong difference in periphyton phosphorus content, A. fluviatilis soft body stoichiometry did not differ between the two nutrient treatments, suggesting strong stoichiometric homeostasis. Furthermore, the distribution of algal biomass was significantly more heterogeneous in the grazed phosphorus‐poor than in the phosphorus‐rich periphyton. Our findings suggest that nutrient enrichment may lead to a weaker top‐down control of algal biomass in stream ecosystems and to reduced spatial heterogeneity of periphyton abundance.

Interplay between r- and K-strategists leads to phytoplankton underyielding under pulsed resource supply.

Fluctuations in nutrient ratios over seasonal scales in aquatic ecosystems can result in overyielding, a condition arising when complementary life-history traits of coexisting phytoplankton species enables more complete use of resources. However, when nutrient concentrations fluctuate under short-period pulsed resource supply, the role of complementarity is less understood. We explore this using the framework of Resource Saturation Limitation Theory (r-strategists vs. K-strategists) to interpret findings from laboratory experiments. For these experiments, we isolated dominant species from a natural assemblage, stabilized to a state of coexistence in the laboratory and determined life-history traits for each species, important to categorize its competition strategy. Then, using monocultures we determined maximum biomass density under pulsed resource supply. These same conditions of resource supply were used with polycultures comprised of combinations of the isolated species. Our focal species were consistent of either r- or K-strategies and the biomass production achieved in monocultures depended on their efficiency to convert resources to biomass. For these species, the K-strategists were less efficient resource users. This affected biomass production in polycultures, which were characteristic of underyielding. In polycultures, K-strategists sequestered more resources than the r-strategists. This likely occurred because the intermittent periods of nutrient limitation that would have occurred just prior to the next nutrient supply pulse would have favored the K-strategists, leading to overall less efficient use of resources by the polyculture. This study provides evidence that fluctuation in resource concentrations resulting from pulsed resource supplies in aquatic ecosystems can result in phytoplankton assemblages' underyielding.

Utilizing External Features and a Consensus Field‐Based Approach to Determine Sex of Lake Michigan Yellow Perch

AbstractUnderstanding fluctuations in population sex ratios is important for evaluating the effects of changes in population demographics and for making informed management decisions. The Yellow Perch Perca flavescens, an important sport fish in Lake Michigan, undergoes sexually dimorphic growth, likely resulting in differing vulnerabilities to angler harvest. However, sex ratio data from angler‐harvested fish have not been collected because of the handling time and intrusiveness of the methods for distinguishing sexes. We utilized digital photographs of the urogenital papilla (UGP) from known‐sex Yellow Perch to establish a method whereby UGP shape could be used to rapidly, accurately, and inexpensively determine the sex of Yellow Perch. Overall, 88.1% of Yellow Perch examined were assigned to the correct sex, and the sex ratio estimate of 48:87 (female : male) did not differ significantly from the known sex ratio of 46:89. Classification success was not affected by fish sex, TL, or month of collection. Our results demonstrate accurate, rapid, inexpensive, and nonlethal applicability of this method across a wide range of sizes and geographic and temporal scales. Applying this methodology will permit accurate sex ratio estimates for angler‐harvested Yellow Perch, which can be used to better understand harvest composition and its implications for management.Received February 17, 2017; accepted June 9, 2017 Published online August 31, 2017

Assessment of Terra MODIS On-Orbit Polarization Sensitivity Using Pseudoinvariant Desert Sites

The Moderate Resolution Imaging Spectroradiometer (MODIS) is currently flying on NASA’s Earth Observing System Terra and Aqua satellites, launched in 1999 and 2002, respectively. MODIS reflective solar bands in the visible wavelength range are known to be sensitive to polarized light based on prelaunch polarization sensitivity tests. After about five years of on-orbit operations, it was discovered that the polarization sensitivity at short wavelengths had shown a noticeable increase. In this paper, we examine the impact of polarization on measured top-of-atmosphere (TOA) reflectances based on MODIS Collection-6 L1B over pseudoinvariant desert sites. The standard polarization correction equation is used in combination with simulated at-sensor radiances using the second simulation of a satellite signal in the Solar Spectrum, Vector Radiative Transfer Code (6SV). We ignore the polarization contribution from the surface and a ratio approach is used for both 6SV-derived input parameters and observed TOA reflectances. Results indicate that significant gain corrections up to 25% are required near the end of scan for the 412 and 443 nm bands. The polarization correction reduces the seasonal fluctuations in reflectance trends and mirror side ratios from 30% and 12% to 10% and 5%, respectively, for the two bands. Comparison of the effectiveness of the polarization correction with the results from the NASA Ocean Biology Processing Group shows a good agreement in the corrected reflectance trending results and their seasonal fluctuations.