Net Accrual Research Articles

Understanding stoichiometric constraints on growth using resource use efficiency imbalances

Growth is a function of the net accrual of resources by an organism. Energy and elemental contents of organisms are dynamically linked through their uptake and allocation to biomass production, yet we lack a full understanding of how these dynamics regulate growth rate. Here, we develop a multivariate imbalance framework, the growth efficiency hypothesis, linking organismal resource contents to growth and metabolic use efficiencies, and demonstrate its effectiveness in predicting consumer growth rates under elemental and food quantity limitation. The relative proportions of carbon (%C), nitrogen (%N), phosphorus (%P), and adenosine triphosphate (%ATP) in consumers differed markedly across resource limitation treatments. Differences in their resource composition were linked to systematic changes in stoichiometric use efficiencies, which served to maintain relatively consistent relationships between elemental and ATP content in consumer tissues and optimize biomass production. Overall, these adjustments were quantitatively linked to growth, enabling highly accurate predictions of consumer growth rates.

Elaborating Strategies of Sustainable Development at Industrial Enterprises

Elaborating strategy of sustainable development at industrial enterprises is a complicated process aimed at designing and introducing such methods of management, which can provide efficient functioning of the enterprise with regard to ecologic, social and economic aspects. This strategy is a key element of successful running of business in current circumstances, where requirements to sustainability and responsibility to the environment are becoming more and more important. The research found the link between the rate of industry sustainability and provision of sustainable development of enterprises in different industries. The article studies factors that can impact the industrial enterprise in the context of sustainable development and shows the dynamics of correlation between industry sustainability rate and finance results of the enterprise. The author proposed an innovative approach that includes using parameters of generated net accruals in the system of efficiency appraisal, as well as figures of corrected net accruals, where their growth shows the effective transfer to sustainable development.

The influence of cyanobacteria blooms on the attenuation of nitrogen throughputs in a Baltic coastal lagoon

We combined a mass balance approach with measurements of air–water and sediment–water nitrogen (N) exchange to better understand the mechanisms attenuating N throughputs in a eutrophic coastal lagoon. We were particularly interested in how seasonal shifts in external versus internal N fluxes and the transition from diatom- to cyanobacteria- dominated phytoplankton communities influence N storage and loss to the atmosphere. We found that on an annual basis almost all of the N removed by the lagoon was due to sediment storage following the spring diatom bloom. This period was characterized by high riverine inputs of dissolved inorganic nitrogen, high rates of assimilatory conversion to particulate nitrogen (PN), and net accrual of N in sediments. By contrast, the larger summer bloom was associated with low sediment N storage, which we attribute in part to the presence of positively-buoyant cyanobacteria. Low settling rates during cyanobacteria blooms favored export of PN to the Baltic Sea over sediment accrual in the lagoon. In addition, summer dinitrogen (N2) fixation by cyanobacteria largely offset annual N2 losses via denitrification. These findings show that cyanobacteria blooms diminish N attenuation within the lagoon by altering the balance of N exchange with the atmosphere and by promoting export of particulate N over sediment burial.

Periphyton biomass accrual rate changes over the colonization process in a shallow mesotrophic reservoir

Abstract Aim: We identified and analyzed the developmental phases (exponential and loss) of periphyton on artificial substrates based on biomass accrual rate in dry and rainy seasons in a shallow mesotrophic reservoir (Ninfeias Reservoir, Parque Estadual das Fontes do Ipiranga, São Paulo, Brazil). We evaluated the colonization time required for the developmental phase to change, as well as related limnological variables. Methods Samplings were carried out weekly, totaling 98 days of substrates exposure. We analyzed the limnological and periphyton variables (chlorophyll a, ash free dry mass, net and gross accrual rate). Results Maximum biomass occurred on the 42nd day in rainy season and on the 98th day in dry season. In the rainy season, the exponential phase of biomass accrual continued until the 28th day of colonization, followed by a fluctuation phase (35th to 77th day) and then a loss phase (84th to 98th days). In the dry season, the exponential phase continued until the 35th day, followed by a loss phase (42th to 63rd day) and then a fluctuation phase (70th and 77th day). In the same season, we observed the beginning of a new exponential phase (84th to 98th day). The biomass peak was recorded on the 42nd colonization day in the rainy season and on the 98th day in the dry season. Biomass and gross and net accrual were higher in the dry season than in the rainy season. Conclusions Periphyton biomass and net and gross accrual rates were higher during the dry season, which was characterized by high total nitrogen concentration, water transparency and low rainfall. We concluded that periphyton biomass accrual and the duration of the developmental phases (exponential, loss and fluctuation) changed with variations in limnological conditions in each climatic period in the tropical shallow reservoir studied.

Mechanical loading causes site-specific anabolic effects on bone following exposure to ionizing radiation

During spaceflight, astronauts will be exposed to a complex mixture of ionizing radiation that poses a risk to their health. Exposure of rodents to ionizing radiation on Earth causes bone loss and increases osteoclasts in cancellous tissue, but also may cause persistent damage to stem cells and osteoprogenitors. We hypothesized that ionizing radiation damages skeletal tissue despite a prolonged recovery period, and depletes the ability of cells in the osteoblast lineage to respond at a later time. The goal of the current study was to test if irradiation prevents bone accrual and bone formation induced by an anabolic mechanical stimulus. Tibial axial compression was used as an anabolic stimulus after irradiation with heavy ions. Mice (male, C57BL/6J, 16weeks) were exposed to high atomic number, high energy (HZE) iron ions (56Fe, 2Gy, 600MeV/ion) (IR, n=5) or sham-irradiated (Sham, n=5). In vivo axial loading was initiated 5months post-irradiation; right tibiae in anesthetized mice were subjected to an established protocol known to stimulate bone formation (cyclic 9N compressive pulse, 60cycles/day, 3day/wk for 4weeks). In vivo data showed no difference due to irradiation in the apparent stiffness of the lower limb at the initiation of the axial loading regimen. Axial loading increased cancellous bone volume by microcomputed tomography and bone formation rate by histomorphometry in both sham and irradiated animals, with a main effect of axial loading determined by two-factor ANOVA with repeated measure. There were no effects of radiation in cancellous bone microarchitecture and indices of bone formation. At the tibia diaphysis, results also revealed a main effect of axial loading on structure. Furthermore, irradiation prevented axial loading-induced stimulation of bone formation rate at the periosteal surface of cortical tissue. In summary, axial loading stimulated the net accrual of cancellous and cortical mass and increased cancellous bone formation rate despite prior exposure to ionizing radiation, in this case, HZE particles. Our findings suggest that mechanical stimuli may prove an effective treatment to improve skeletal structure following exposure to ionizing radiation.

Accruals: An overview

The paper provides a broad discussion of the topic “accruals”. Though much of what is said is familiar from the literature on accruals, the paper tries to develop concepts and show how theses forge tight links across a variety of themes. The starting point of the analysis concerns the construct of an accrual. The case is made that it should rest solely on consecutive balance sheets and the splitting of assets/liabilities into (i) cash and approximate cash, assets/liabilities and (ii) all other kinds of assets/liabilities. Given this divide of assets/liabilities one can measure the components in the foundation equation: cash earnings+net accrual=comprehensive earnings. The paper then proceeds to discuss how the net accrual relates to growth in a firm’s operating activities and the extent to which it can be informative or misleading. This topic in turn integrates with the issue of a firm’s quality of earnings and the role of accounting conservatism. Among the remaining topics, the paper discusses how one conceptualizes diagnostics to assess whether or not a period’s accrual is likely to be biased upwards or downwards. It gives rise to a consideration of how one constructs accruals that may be more informative than GAAP accruals and the role of value-relevance studies to assess the information content of accrual constructs. The paper ends with a list of suggestions how future research may be modified in light of the discussions in this paper.

Evaluating Earnings Management in Financial Institutions

Most companies listed on the Standard & Poor’s 500 (S&P 500) index have smoothed reported earnings since the 1990s inspiring questions from regulators about the accuracy of financial statements. In 2002, the Sarbanes-Oxley Act (SOX) was issued to eradicate earnings management activities and improve transparency in financial reporting. Although many studies have been conducted to evaluate changes in reporting requirements, much less is known about the effectiveness of these regulations on earning smoothing with discretionary accruals (DA). Accordingly, this study was an investigation of DA from 2002 to 2011. In addition, this study included an evaluation of DA before and after the financial crisis of 2008. This study is a quasi-experimental research design where 330 observations from the U.S. financial industry segment were used for the analysis. The Modified Jones model was used to separate DA and repeated measures analyses of variance were used to assess differences in levels before and after the financial crisis of 2008. The findings suggest DA activities are decreasing but represent over 50% of total net accruals (TNA) for all years. Improved financial regulation is needed. The study contributes to positive social change by providing regulators and investors with new information about accruals for income conservative firms by segmenting DA within the financial industry segment.

Malformation syndromes caused by disorders of cholesterol synthesis

Cholesterol homeostasis is critical for normal growth and development. In addition to being a major membrane lipid, cholesterol has multiple biological functions. These roles include being a precursor molecule for the synthesis of steroid hormones, neuroactive steroids, oxysterols, and bile acids. Cholesterol is also essential for the proper maturation and signaling of hedgehog proteins, and thus cholesterol is critical for embryonic development. After birth, most tissues can obtain cholesterol from either endogenous synthesis or exogenous dietary sources, but prior to birth, the human fetal tissues are dependent on endogenous synthesis. Due to the blood-brain barrier, brain tissue cannot utilize dietary or peripherally produced cholesterol. Generally, inborn errors of cholesterol synthesis lead to both a deficiency of cholesterol and increased levels of potentially bioactive or toxic precursor sterols. Over the past couple of decades, a number of human malformation syndromes have been shown to be due to inborn errors of cholesterol synthesis. Herein, we will review clinical and basic science aspects of Smith-Lemli-Opitz syndrome, desmosterolosis, lathosterolosis, HEM dysplasia, X-linked dominant chondrodysplasia punctata, Congenital Hemidysplasia with Ichthyosiform erythroderma and Limb Defects Syndrome, sterol-C-4 methyloxidase-like deficiency, and Antley-Bixler syndrome.

Inverse model method for estimating assimilation by aquatic invertebrates

Physiological data indicate that a 3-compartment model appropriately represents ingestion, assimilation, and accumulation of somatic and reproductive tissue by an aquatic invertebrate predator. A secondary production model calibrated to growth and respiration data is used to constrain the model equations. Inverse solution methods are used to estimate rate constants for digestion and for net accrual of tissue by growing animals at different temperatures. Predicted time to 50% maximum digestion matches well with the empirical rate of digestion of prey enzymes in the predator gut. Model-derived digestion rates are consistent with the assimilation rate constant obtained by independent radiotracer methods, and with experimental detection time for prey enzymes. The model approach permits parameter estimation within a complex system of equations so that results can be compared with experimental data.

Utilization of bicarbonate for base repletion in hemodialysis.

Because of physiochemical considerations, acetate rather than bicarbonate has traditionally been used as the base repletion agent in dialysate. There are major differences in the mechanisms through which these agents neutralize the body's acid load in the circumstance of dialysis. Acetate dialysis relies on metabolism of acetate to generate bicarbonate. Loss of bicarbonate into the dialysate requires that acetate dialysis supply base far in excess of that required to buffer metabolic hydrogen ion generation alone. Consequently, net accrual of base is difficult to quantitate and may be inadequate to neutralize the excess hydrogen ion, leading to chronic buffer depletion. However, acute acid-base problems are usually avoided because of the indirect nature of base addition. In contrast, net base accrual with bicarbonate dialysis occurs in a direct and quantitative manner. While inadequate base repletion is avoided, the direct addition of base requires much tighter control if undesirable acute changes in blood pH are to be avoided.

Icebergs for reservoirs, fresh water and cooling

Icebergs provide unique reservoirs with significant net accrual of condensation water over evaporation loss. They are relatively invulnerable to earthquakes and other disasters and do not threaten the surrounding marine environment. They do not permanently displace large areas from other potential uses, and they are flexable in size to accommodate changing needs. Impressive amounts of heat or energy are required to convert icebergs for their fresh water of exceptional quality. However, their use in a warm environment offers opportunities to extract the heat from the environment with little energy cost. The cooling capacity of icebergs could be used to improve the efficiency of conventional electrical power generation, and there are proposals to use icebergs in a much warmer environment as a means of generating power. A variety of techniques may be developed for conversion, however a simple way requiring little development for early use augments the natural heat exchange with the atmosphere by means of sprays which increase the condensation of water vapor and the extraction of heat from the atmosphere. The energy used for this method of conversion is typically equivalent to lifting the delivered water less than 60 meters. An illustration of the average annual natural heat flow rates across a freezing horizontal surface in watts per square meter represntative of San Diego, California are the following: solar insolation 186, atmospheric radiation 290, atmospheric convection 113, heat of condensation 139, and gray body surface radiation 306. This leaves a net input rate of 422 for melting which would melt a depth of 37.5 meters per year. The condensation would be an additional 1.71 meters of water per year. These data have been abstracted from unpublished studies.