Cumulative Balance Research Articles

The Roles of RFamide‐Related Peptide‐3 in Mammalian Reproductive Function and Behaviour

To maximise reproductive success, organisms restrict breeding to optimal times of the day or year, when internal physiology and external environmental conditions are suitable for the survival of both parent and offspring. To appropriately coordinate reproductive activity, internal and external standing is communicated to the hypothalamic-pituitary-gonadal axis via a coordinated balance of stimulatory and inhibitory neurochemical systems. The cumulative balance of these mediators ultimately drives the pattern of gonadotrophin-releasing hormone secretion, a neurohormone that stimulates pituitary gonadotrophin secretion. Until 2000, a complementary inhibitor of pituitary gonadotrophin secretion had not been identified. At this time, a novel, avian hypothalamic peptide capable of inhibiting gonadotrophin secretion in cultured quail pituitary cells was uncovered and named gonadotrophin-inhibitory hormone (GnIH). Subsequently, the presence and functional role for the mammalian orthologue of GnIH, RFamide-related peptide, (RFRP-3), was examined, confirming a conserved role for this peptide across several rodent species. To date, a similar distribution and functional role for RFRP-3 have been observed across all mammals investigated, including humans. This overview summarises the role that RFRP-3 plays in mammals and considers the implications and opportunities for further study with respect to reproductive physiology and the neural control of sexual behaviour and motivation.

Glacier changes at Svartisen, northern Norway, during the last 125 years: Influence of climate and other factors

The two ice caps of Svartisen, at the latitude of the Arctic Circle in Norway, supply 60 glaciers, ranging in size from >50 to <1 km2. Until the last two decades of the 19th century, the glaciers remained close to their maximum recent (Little Ice Age) size. In response to the prevailing 20th century climate, they have become smaller, but the changes have varied between glaciers. Climatic factors have not been the sole control of the variations. The response times of small, steep glaciers are shorter than those of the longer, more gently sloping outlet glaciers. Topographic factors may moderate the response of individual glaciers to climate. The 20th century mass balance of several of the larger glaciers was dominated by calving into marginal lakes. The mass balance of Engabreen, the largest outlet of the western ice cap, has been measured every year since 1970 and the cumulative balance to 2008 was a gain of 22.7 m water equivalent. Although the pattern of annual variations probably applies to the other glaciers of Svartisen, it does not indicate their actual changes (gain or loss). Thus, the Engabreen record is of little utility in water resource planning for the whole area.

How Viable are Unemployment Insurance Savings Accounts? Simulation Results for Slovenia

Applying a methodology similar to Feldstein and Altman (1998) to Slovenia's unemployment insurance (UI) system, the paper shows that unemployment insurance savings accounts (UISAs) are a viable alternative to a modest, but not generous, UI system. Under the modest regime, only one quarter of workers end their working life with a negative cumulative balance and 43% ever experience a negative UISA balance; in contrast, under the generous regime, 49% of workers end their working life with a negative cumulative balance and 66% ever experience a negative balance. The simulations also show that the level of redistribution under UISAs lags behind the redistribution implied by the UI system.

Optimal nutrition during the period of mechanical ventilation decreases mortality in critically ill, long-term acute female patients: a prospective observational cohort study

IntroductionOptimal nutrition for intensive care patients has been proposed to be the provision of energy as determined by indirect calorimetry, and protein provision of at least 1.2 g/kg pre-admission weight per day. The evidence supporting these nutritional goals is based on surrogate outcomes and is not yet substantiated by patient oriented, clinically meaningful endpoints. In the present study we evaluated the effects of achieving optimal nutrition in ICU patients during their period of mechanical ventilation on mortality.MethodsThis was a prospective observational cohort study in a mixed medical-surgical, 28-bed ICU in an academic hospital. 243 sequential mixed medical-surgical patients were enrolled on day 3–5 after admission if they had an expected stay of at least another 5–7 days. They underwent indirect calorimetry as part of routine care. Nutrition was guided by the result of indirect calorimetry and we aimed to provide at least 1.2 g of protein/kg/day. Cumulative balances were calculated for the period of mechanical ventilation. Outcome parameters were ICU, 28-day and hospital mortality.ResultsIn women, when corrected for weight, height, Apache II score, diagnosis category, and hyperglycaemic index, patients who reached their nutritional goals compared to those who did not, showed a hazard ratio (HR) of 0.199 for ICU mortality (CI 0.048–0.831; P = 0.027), a HR of 0.079 for 28 day mortality (CI 0.013–0.467; P = 0.005) and a HR of 0.328 for hospital mortality (CI 0.113–0.952; P = 0.04). Achievement of energy goals whilst not reaching protein goals, did not affect ICU mortality; the HR for 28 day mortality was 0.120 (CI 0.027–0.528; P = 0.005) and 0.318 for hospital mortality (CI 0.107–0.945; P = 0.039). No difference in outcome related to optimal feeding was found for men.ConclusionsOptimal nutritional therapy improves ICU, 28-day and hospital survival in female ICU patients. Female patients reaching both energy and protein goals have better outcomes than those reaching only the energy goal. In the present study men did not benefit from optimal nutrition.

Soil phosphorus monitoring at the regional level by means of a soil test database

AbstractThe practice of applying large amounts of P to agricultural land over several previous decades, particularly in regions with intensive livestock production, has resulted in P accumulation in soils with an increased risk of P losses into water bodies and thus of eutrophication. This work is aimed at analyzing the spatiotemporal changes in extractable soil P content at the regional level by means of a soil test database and then comparing results with independent data from agricultural censuses. A total of 228 079 soil P‐test values [Dyer method: 1:5 soil‐citric acid solution (20 g/L) ratio] generated between 1980 and 2003 by certified commercial laboratories in Brittany (northwestern France) were integrated into a database. Changes in P were analysed by considering four 4–6 year periods between 1980 and 2003 using cumulative frequencies and summary statistics performed on raw soil test values. Then data were aggregated into discrete entities (canton: administrative entities) and summary statistics, linear regression and spatial distribution were carried out. P balances were measured for the same entities taken from the agricultural censuses of 1979, 1988 and 2000. Over the entire study period, a marked spatial variability was observed with higher P content in the western part of Brittany, as well as a systematic increase in median P content with lower amplitude over the past decade. The mean cantonal soil P surplus accumulated over 24 years amounted to 763 kg P/ha of usable agricultural land. Similar P balances sometimes gave rise to widely different increases in P. Cumulative balances were positively correlated with an increase in soil P (r2 = 0.34).

A DOUBLE-BLIND RANDOMIZED, CONTROLLED TRIAL OF PROTEIN ENERGY–ENRICHED FORMULA ADMINISTERED TO CRITICALLY ILL INFANTS

INTRODUCTION: Nutritional support is an important aspect of clinical management of critically ill infants, but the nutritional requirements of these infants are not well defined. OBJECTIVE: Our goal was to compare tolerance, nutritional, and metabolic effects of 2 different infant formulas in critically ill infants in a double-blind, randomized way. METHODS: Eighteen ventilated infants with respiratory insufficiency caused by respiratory syncytial virus infection were included and received an energy- and protein-enriched (PE) infant formula (Infatrini [Nutricia B. V. Zoetermeer, Zoetermeer, Netherlands]; n = 8) or standard infant formula (Nutrilon 1 [Nutricia B. V. Zoetermeer]; n = 10). Daily intake and tolerance (gastric retention, diarrhea) were recorded. Resting energy expenditure, respiratory quotient, L-amino acid concentrations, and metabolic parameters were measured, and cumulative energy balance, nitrogen balance, and substrate utilization were calculated. RESULTS: Baseline characteristics were similar in both groups. Both formulas were well tolerated with similar volumes of intake. Results from day 4 are presented in Table 1. Levels of several amino acids (His, Val, Met, Phe, Lys, and ornithine; P &amp;lt; .05) were significantly higher in the infants who received the PE-enriched formula. CONCLUSIONS: PE-enriched infant formula was well tolerated in critically ill infants and effective in achieving higher nutritional intakes in the first days of admission. PE-enriched formula improved energy balance and plasma amino acid profile, and a trend toward increased nitrogen balance was found. TABLE 1.Results on Day 4 of AdmissionFormulaProtein Intake, g/kg per dayEnergy Intake, kcal/kg per dayaResting Energy Expenditure, kcal/kg per dayaRespiratory QuotientCumulative Energy Balance, kcal/kg per dayaCumulative Nitrogen Balance, mg/kg per dayPE-enriched (n = 8)2.61 ± 0.24111 ± 1059 ± 50.98 ± 0.02589 ± 115162 ± 32Standard (n = 10)1.46 ± 0.1178 ± 449 ± 40.91 ± 0.01350 ± 5068 ± 16 P &amp;lt;.01&amp;lt;.01.26&amp;lt;.01&amp;lt;.05.08a1 kcal = 4.2 kJ.

Glaciological and volumetric mass-balance measurements: error analysis over 51 years for Glacier de Sarennes, French Alps

AbstractThe mass balance of Glacier de Sarennes, French Alps, has been measured since 1949, using the glaciological method based on core and ablation stake data, and area extrapolations, to find the overall glacier balance. The cumulative balance obtained in this way is very dependent on systematic errors that can increase linearly with the number, N, of measurement years, whereas random errors rise with . The volumetric-balance method based on aerial photogrammetry provides results whose errors do not depend on the number of years. This method was used to test field measurements for the period 1952–2003 and gives a mass balance of −32.30 ± 1.04 m w.e. compared to −34.89 ± 1.15 m w.e. based on field data. The discrepancy between the two methods is discussed on the basis of a careful error analysis. Moreover, the possibility of using the volumetric method to detect biases in field measurements is evaluated in terms of two types of errors. The number and locations of measurement sites required to account for all the spatial and temporal variabilities of the mass balance is discussed by variance analysis. Methodological implications and recommendations are presented to provide mass-balance measurements of the best possible accuracy.

The influence of volume management on outcome

Fluid (volume) therapy is an integral component in the management of critically ill patients and fluid management may influence outcome. There is much controversy, however, about the type, timing and amount of fluid therapy. Here, we discuss the evidence available to guide such choices. Fluid therapy is widely endorsed for resuscitation of critically ill patients across a range of conditions. Yet, the approach to fluid therapy is subject to substantial variation in clinical practice. Emerging data show that the choice, timing and amount of fluid therapy may affect clinical outcomes. Synthetic colloids may increase the risk of acute kidney injury. Albumin may benefit hypoalbuminemic patients with sepsis and acute lung injury but may worsen outcome in traumatic brain injury. Early administration of fluid therapy in sepsis may improve survival but may be unnecessary in patients with penetrating trauma. Later fluid therapy in acute lung injury patients will increase the duration of ventilator dependence without achieving better survival. A positive cumulative balance likely contributes to increased morbidity and mortality after major surgery. Emerging evidence shows that choice, timing and amount of fluid therapy affect outcome. Future studies need to focus on these aspects of fluid therapy by means of larger, more rigorous and blinded controlled trials.

Comment on “Is it now time to promote mixed enteral and parenteral nutrition for the critically ill patient?” by Heidegger et al.

Sir: Heidegger and colleagues reviewed the recent findings regarding the nutritional support of critically ill patients, and since most of the studies showed that enteral nutritional support was insufficient, they proposed to promote parenteral nutrition [1]. Definitively, the current manner in which enteral feeding is delivered in the ICU is inadequate regarding the target and leads to increased morbidity and perhaps mortality [2]. We also agree that tight glucose control together with prevention of catheter bloodstream-related sepsis have decreased the complications related to parenteral nutrition [3]. However, their proposition may not prevent feeding-related complications if they are not associated with a recommendation to determine precisely the calorie target. It has been known for years that most of the predictive formulas or the ACCN recommendations are far from measured requirements obtained by indirect calorimetry [4]. Most of the data available about calorie deficit and complications are based on measured energy requirements. Adding parenteral nutrition according to incorrect formulas may lead to overor underfeeding and to complications. Until now the routine use of metabolic carts remains unusual in critical care settings (17% of the Europeans PICUs in the only survey of 111 units available [5]) despite the fact that most of the authors agree that when you can use the metabolic cart, you should do so [6]. There is no randomized prospective study demonstrating the advantages of a metabolic cart in the critical care setting, but there are no such studies for other monitoring devices either. However, the added values of measurements obtained by a metabolic cart are numerous: daily changes in energy expenditure (up to 46% changes), cumulative energy balance during the ICU stay (as important as water balance), maximum negative energy balance which is best correlated with the occurrence of complications [2], and VO2 and VCO2 values that can guide level of sepsis and degree of metabolic rate. Overall, as in intensive insulin therapy based on glycemic measurements, tailored calorie intake based on metabolic cart measurements will improve the nutritional support. To demonstrate the benefits of the parenteral approach a randomized controlled trial based on measured energy requirements would be the most appropriate approach. Lord Kelvin, who helped Joule to construct the modern kinetic theory of heat, and of the centenary of whose death we are now marking stated: “When you can measure what you are speaking about, and express it in numbers, you know something about it. If you cannot measure it, you cannot improve it.” References

Crop residue, manure and fertilizer in dryland maize under reduced tillage in northern China: II nutrient balances and soil fertility

A long-term experiment was carried out in the dryland of northern China to assess the effects of applications of maize stover, cattle manure and NP (1:0.44) fertilizer on partial nitrogen (N), phosphorus (P) and potassium (K) balances, extractable soil N (SEN), P and K, and soil organic matter (SOM) in a spring maize cropping system, under reduced tillage conditions. The experiment was set-up according to an incomplete, optimal design, with three factors at five levels and 12 treatments, including a control with two replications. Statistical analyses using multiple regression models showed that the partial N, P and K balances were strongly influenced by annual variations in the amounts of soil water at seeding (SWS) and growing season rainfall (GSR). Most treatments had positive P but negative N and K balances. Cumulative P and K balances were reflected in extractable soil P (P-Olsen) and K (exchangeable K), but the weak relationships indicated that the sorption of P and buffering of K were strong. Cumulative balances of effective organic carbon (C) were weakly related to soil organic C (SOC) content after 12 years. Negative C balances were related to decreases in SOC, but positive C balances were not translated into increases in SOC. The analysis of nutrient balances and soil fertility indices revealed that nutrient inputs in most treatments were far from balanced. It is concluded that the concepts of ‘ideal soil fertility level’ and ‘response nutrient management’ provide practical guidelines for improving nutrient management under the variable rainfall conditions of dry land areas in northern China.

Indirect calorimetry: relevance to patient outcome.

Indirect calorimetry provides an important adjunctive monitor for the provision of nutrition support in the critically ill patient. Accuracy in determining caloric requirements may serve to optimize benefit from nutrition therapy and improve patient outcome. A number of strategies in nutrition management in the intensive care setting (eg, dosing of enteral nutrition, monitoring cumulative caloric balance, and deliberate but "permissive" underfeeding) necessitate the determination of a fairly specific goal for caloric provision. Inaccuracy leading to inappropriate under- or overfeeding may generate additional morbidity and adverse clinical consequences for patients already at high risk from hypermetabolic stress response to injury.

The current disequilibrium of North Cascade glaciers

AbstractThree lines of evidence indicate that North Cascade (Washington, USA) glaciers are currently in a state of disequilibrium. First, annual balance measured on nine glaciers yields a mean cumulative balance for the 1984–2004 period of −8·58 m water equivalent (w.e.), a net loss of ice thickness exceeding 9·5 m. This is a significant loss for glaciers that average 30–50 m in thickness, representing 18–32% of their entire volume.Second, longitudinal profiles completed in 1984 and 2002 on 12 North Cascade glaciers confirm this volume change indicating a loss of −5·7 to −6·3 m in thickness (5·0–5·6 m w.e.) between 1984 and 2002, agreeing well with the measured cumulative balance of −5·52 m w.e. for the same period. The change in thickness on several glaciers has been equally substantial in the accumulation zone and the ablation zone, indicating that there is no point to which the glacier can retreat to achieve equilibrium. Substantial thinning along the entire length of a glacier is the key indicator that a glacier is in disequilibrium.Third, North Cascade glacier retreat is rapid and ubiquitous. All 47 glaciers monitored are currently undergoing significant retreat or, in the case of four, have disappeared. Two of the glaciers where mass balance observations were begun, Spider Glacier and Lewis Glacier, have disappeared. The retreat since 1984 of eight Mount Baker glaciers that were all advancing in 1975 has averaged 297 m. These observations indicate broad regional continuity in glacial response to climate. Copyright © 2006 John Wiley &amp; Sons, Ltd.

The effect of cumulative energy and protein deficiency on anthropometric parameters in a pediatric ICU population

Background & Aims: Nutritional support is essential in the care of critically ill children since inadequate feeding increases morbidity and negatively affects growth. We aimed to compare cumulative energy and protein intakes with recommended dietary intakes (RDA) and examine relationships between accumulated balances and anthropometric parameters.Methods: Prospective, observational study. Total daily energy and protein intakes were determined during a maximum of 14 days in 261 children admitted to our multidisciplinary tertiary pediatric ICU. Actual intakes were subtracted from RDA and cumulative balances were calculated. Relations between cumulative balances, various clinical factors and changes in anthropometry (weight, arm and calf circumference) were analyzed using regression analysis.Results: At 14 days after admission children showed significant cumulative nutritional deficits compared to RDA. These deficits were on average 27, 20, 12 kcal/kg and 0.6, 0.3, and 0.2g protein/kg per day for preterm neonates (n=103), term neonates (n=91) and older children (n=67), respectively. Age at admission, length of ICU-stay and days on mechanical ventilation were negatively related to cumulative balances. Cumulative energy and protein deficits were associated with declines in SD-scores for weight and arm circumference.Conclusions: Children admitted to the ICU accumulate substantial energy and protein deficits when compared to RDA. These deficits are related to decreases in anthropometric parameters.

Comparison of geodetic and glaciological mass-balance techniques, Gulkana Glacier, Alaska, U.S.A.

AbstractThe net mass balance on Gulkana Glacier, Alaska, U.S.A., has been measured since 1966 by the glaciological method, in which seasonal balances are measured at three index sites and extrapolated over large areas of the glacier. Systematic errors can accumulate linearly with time in this method. Therefore, the geodetic balance, in which errors are less time-dependent, was calculated for comparison with the glaciological method. Digital elevation models of the glacier in 1974, 1993 and 1999 were prepared using aerial photographs, and geodetic balances were computed, giving – 6.0 ± 0.7 m w.e. from 1974 to 1993 and -11.8 ± 0.7 m w.e. from 1974 to 1999. These balances are compared with the glaciological balances over the same intervals, which were – 5.8 ± 0.9 and -11.2 ± 1.0 m w.e. respectively; both balances show that the thinning rate tripled in the 1990s. These cumulative balances differ by &lt;6%. For this close agreement, the glaciologically measured mass balance of Gulkana Glacier must be largely free of systematic errors and be based on a time-variable area-altitude distribution, and the photography used in the geodetic method must have enough contrast to enable accurate photogrammetry.

High correlation between increased negative calorie balance and morbidity in critically ill patients

Accurate energy balance is difficult to assess since prescribed energy intake is not always actual energy intake administered, intravenous dextrose given as part of a fluid program is not always taken into account and resting energy expenditure (REE) is not usually measured on a daily basis. We used a bedside computerized information system to measure daily and cumulative energy balance in critically ill ventilated patients to assess its impact on patient outcome.

A macroscopic approach to glacier dynamics

AbstractA simple approach to glacier dynamics is explored in which there is postulated to be a relationship between area and volume with three parameters: the time for area to respond to changes in volume, a thickness scale, and an area characterizing the condition of the initial state.This approach gives a good fit to the measurements of cumulative balance and area on South Cascade Glacier from 1970–97; the area time-scale is roughly 8 years, the thickness scale about 123 m, and the 1970 area roughly 4% larger than required for adjustment with volume. Combining this relationship with a version of mass continuity expressed in terms of area and volume produces a theory of glacier area and volume response to climate in which another time constant, the volume time-scale, appears. Area and volume both respond like a damped spring and mass system. The damping of the South Cascade response is approximately critical, and the volume time-scale is roughly 48 years, six times the area time-scale. The critically damped spring and mass analogy reproduces the time dependence predicted by the more complicated traditional theory of Nye.

The surges of Variegated Glacier, Alaska, U.S.A., and their connection to climate and mass balance

AbstractOne of the questions still unanswered concerning the surge behavior of glaciers concerns their quasi-periodic occurrence. Some results on the phenomenological connection between local cumulative balance and surge initiation of Variegated Glacier, Alaska, U.S.A., are discussed here. Based on climate data from neighboring weather stations, an empirical relation between precipitation, temperature and local mass balance is established and used to reconstruct the annual balance at a location in the accumulation area back to 1905. Between the last four surges in 1946/47, 1964/65, 1982/83 and 1994/95, the ice-equivalent cumulative balance was 43.5 m on average, with a 1σ error of 1.2 m. Although the existence of a surge level cannot be directly interpreted in physical terms, it explains the variable length of the quiescent periods of Variegated Glacier by variations in the accumulation rate prior to the surge. We use the surge level to hindcast former unobserved surges, to compare the results with other surge datings obtained from photographs and to establish a complete surge history for Variegated Glacier for the 20th century.

Analysis of difference between direct and geodetic mass balance measurements at south cascade glacier, washington

Net mass balance has been measured since 1958 at South Cascade Glacier using the ‘direct method,’ e.g. area averages of snow gain and firn and ice loss at stakes. Analysis of cartographic vertical photography has allowed measurement of mass balance using the ‘geodetic method’ in 1970, 1975, 1977, 1979–80, and 1985–97. Water equivalent change as measured by these nearly independent methods should give similar results. During 1970–97, the direct method shows a cumulative balance of about −15 m, and the geodetic method shows a cumulative balance of about −22 m. The deviation between the two methods is fairly consistent, suggesting no gross errors in either, but rather a cumulative systematic error. It is suspected that the cumulative error is in the direct method because the geodetic method is based on a non‐changing reference, the bedrock control, whereas the direct method is measured with reference to only the previous year's summer surface. Possible sources of mass loss that are missing from the direct method are basal melt, internal melt, and ablation on crevasse walls. Possible systematic measurement errors include under‐estimation of the density of lost material, sinking stakes, or poorly represented areas.

Indirect calorimetry: can this technology impact patient outcome?

This review of 23 papers involving indirect calorimetry published over the past 18 months shows how our understanding of the metabolic response to injury has changed, highlights the problems introduced by use of predictive equations and alterations in indirect calorimetry testing protocol, and emphasizes the need to monitor cumulative energy balance by comparing daily caloric intake to energy expenditure.

On the controllability of nonlinear economic systems with delay: The Italian example

The dynamic model of some key economic indicators – the gross national product, GNP, interest rate, R, employment, L, value of capital stock, k, prices, p, and cumulative balance of payment, E – are derived here from mathematical and economic principles. The model is described by a hereditary ordinary differential equation, a nonlinear delay differential pursuit game of neutral type. The quarry control-solidarity or government intervention consists of money supply, M, government budget, net expenditure, taxation, T, exchange rate, e, tariffs, foreign credit fo, distance between trading partners or trading arrangements d, or preferential arrangement. The pursuer control (private initiative) consists of autonomous private consumption, investment, net export, labor productivity, money wage rate w, autonomous money demand m, income autonomous consumption y 10. Conditions are established for the variables of the economic indicators to be controllable from one initial function to a terminal function, in particular, employment, national income and prices can be controlled from one arbitrary vector function to another when the controls of the system are subject to scarcity, i.e., to constraints. Conditions for controllability are presented. Our model is tested with data on Italian economy. This paper opens up the hope that full employment, high income growth is compatible with low prices and low inflation, provided the control matrix has full rank, i.e., the existing controls are fully effectively used.