Biophysical Monitoring Research Articles

Satellite Microwave Remote Sensing of Boreal and Arctic Soil Temperatures From AMSR-E

Methods are developed and evaluated to retrieve surface soil temperature information for the advanced microwave scanning radiometer on earth observing system for seven boreal forest and Arctic tundra biophysical monitoring sites across Alaska and Northern Canada. A multiple-band iterative radiative transfer process-based method producing dynamic vegetation and snow cover correction quantities and an empirical multiple regression method using several frequencies are employed. The seasonal pattern of microwave emission and relative accuracy of the soil temperature retrievals are influenced strongly by landscape properties, including the presence of open water, vegetation type and seasonal phenology, snow cover, and freeze-thaw transitions. The retrieval of soil temperature is similar for the two methods with an overall root-mean-square error of 3.1-3.9 K during summer thawed conditions, with a larger error occurring in winter during periods of dynamic snow cover and freeze-thaw state. These results indicate that at high latitudes, the influence of the atmosphere may be less important than that of surface conditions in determining the relative accuracy of the estimated soil temperature. Impacts of surface conditions on surface emissivity, observed brightness temperature, and estimated soil temperature are discussed.

Socio-economic effects monitoring: toward improvements informed by bio-physical effects monitoring

In this paper, using two case studies from the Hibernia offshore platform construction project, we argue that follow-up based on the hypothesistesting approach typically adopted in biophysical effects monitoring could be more widely adopted in socio-economic effects monitoring. While there are some significantly different issues associated with socio-economic and biophysical monitoring, we argue that such an approach in the socio-economic context would encourage more focused attention on monitoring objectives, more appropriate data collection and clearer identification of project-specific impacts, thereby offering more credible and useful information to decision-makers than is now often the case.

Management of fetuses with absent/reversed end-diastolic flow (AREDF) in the umbilical artery: outcome of a policy of daily biophysical profile (BPP)

This study aimed to evaluate a management strategy of daily BPP for fetuses with AREDF in the umbilical artery. This was a retrospective review (1994–2002) of outcome in 133 non-anomalous fetuses with AREDF referred to a tertiary centre. Delivery was timed on the basis of an abnormal BPP or gestation > 34 weeks. The mean (SD) gestation at diagnosis was 28.8 (4.4) weeks, and at delivery was 30.4 (4.2) weeks. There were 42 (32%) perinatal deaths, including 30 (23%) in-utero deaths [birth weight 521 (196) g], seven (5%) neonatal deaths [715 (128) g] and seven (5%) terminations of pregnancy [389 (141) g]. Mean birth weight of surviving infants was 1326 (727) g. For the 96 livebirths, 20 (21%) were delivered at gestation ≥ 34 weeks, 11 (11%) for pre-eclampsia and 44 (46%) for abnormal biophysical monitoring (17 for a BPP score =4/10, nine for two equivocal BPPs (score 6/10) and 18 for a single equivocal BPP (of which the key prompt in eight was a pathological CTG). A pathological CTG prompted delivery in a further 12 fetuses where the ultrasound components of the BPP were normal (i.e. 8/8). There was one abruption, and eight (8%) babies delivered for other reasons. ‘Unexpected’ IUDs (i.e. within 24 hours of a normal BPP) occurred in five (4%) cases between 26+1 and 29+0 weeks. These pregnancies were complicated by either proteinuric hypertension (three) or preterm amniorhexis (two). In one case, an equivocal BPP was not repeated within 24 hours.

Towards operational monitoring of terrestrial systems by moderate-resolution remote sensing

The Moderate Resolution Imaging Spectroradiometer (MODIS) sensor is providing a series of products of unparalleled quality and sophistication for the observation and biophysical monitoring of the terrestrial environment. The capabilities of the MODIS sensor of NASA's Terra and Aqua platforms, in observing the terrestrial environment, are a precursor to the operational capabilities of the National Polar Operational Environmental Satellite System (NPOESS) series of missions, which will succeed the current polar operational capabilities of the NOAA series of satellites. Prior to NPOESS, the NPOESS Preparatory Project (NPP) will be launched, acting as a bridge between the two MODIS instruments and the longer term advanced operational capability. The result of these missions will be the establishment of long-term systematic, operational capabilities. Notwithstanding the improvements arising from these missions, there are many lessons to be learnt from current experiences in using MODIS data. Moreover, the timing of the implementation of these missions will provide challenges to users. Additionally, agencies must anticipate a rapid evolution of requirements associated with burgeoning terrestrial programs such as Global Observations of Forest Cover/Global Observations of Landcover Dynamics (GOFC/GOLD) and Terrestrial Carbon Observations (TCO).

Using farmers' knowledge for defining criteria for land qualities in biophysical land evaluation

AbstractThe objective of this paper is to present a way of complementing empirical results with farmers' perceptions in defining limiting biophysical land properties in a land suitability evaluation using the FAO framework methodology. The farmers' perceptions were identified using rapid and participatory rural appraisal (RRA/PRA) tools. The study catchment, having a semiarid continental climate and located on the Loess Plateau in northern China, covered an area of 3.5 km2. Most of the land users were dependent on subsistence agriculture. There were important topographic variations in the catchment and arable cropping on steep slopes brought about degradation of land due to water erosion. The biophysical monitoring, soil survey and RRA/PRA survey, carried out one year prior to the present investigation, supplied the data needed for identification of preliminary limiting land properties and land evaluation units. The land properties that needed further investigation in the present study were slope aspect, soil workability, flooding hazard and farmers' criteria on choice of land‐use type. The farmers were able to give a comprehensive picture of the spatial and temporal variation and the importance for land‐use options of the land properties concerned, and thereby complement the information gained from empirical results (measurements). In order to guarantee good production for dry as well as wet years, both south‐ and north‐facing sites were chosen for most crops, and the slope aspect did not need to be differentiated in the final land suitability evaluation for arable crops. Grassland, however, was considered to be more suitable than woodland on south‐facing sites. Hard soil layers were found to be important, since they affected soil workability and erosion negatively, giving slightly reduced suitability for the land units in which they occurred. Flooding events affecting crops on alluvial soils negatively were considered to occur once every 5 to 10 years, which is considered to be a low rate, so this property was therefore not included in the final suitability evaluation. Copyright © 2001 John Wiley & Sons, Ltd.

Analysis of Fetal Movements by Doppler Actocardiogram and Fetal B-Mode Imaging

We have presented that fetal surveillance may be enhanced by use of the fetal actocardiogram and by computerized processing of fetal motion as well as fetal B-mode ultrasound imaging. Ultrasonic Doppler fetal actogram is a sensitive and objective method for detecting and recording fetal movements. Computer processing of the actograph output signals enables powerful, detailed, and convenient analysis of fetal physiologic phenomena. The actocardiogram is a useful measurement tool not only in fetal behavioral studies but also in evaluation of fetal well-being. It reduces false-positive, nonreactive NST and false-positive sinusoidal FHR pattern. It is a valuable tool to predict fetal distress. The results of intrapartum fetal monitoring are further improved by the antepartum application of the actocardiogram. Quantified fetal motion analysis is a useful, objective evaluation of the embryo and fetus. This method allows monitoring of changes in fetal movement, as well as frequency, amplitude, and duration. Furthermore, quantification of fetal motion enables evaluation of fetal behavior states and how these states relate to other measurements, such as changes in FHR. Numeric analysis of both fetal actogram and fetal motion from B-mode images is a promising application in the correlation of fetal activity or behavior with other fetal physiologic measurements.

Biophysical testing in premature rupture of the membranes

The management of pregnancies complicated by premature rupture of the membranes (PROM) should include some type of surveillance for the development of infectious complications. This is a necessity because neonatal sepsis is not heralded by maternal chorioamnionitis in the majority of cases. Fetal biophysical assessment holds promise as a method to assess fetal well-being and predict the development of infectious complications. The frequent use of fetal biophysical profiles in patients with PROM helps to distinguish healthy fetuses from those infected or at high risk of infection. This distinction enables the physician to intervene appropriately and in a timely manner. The recognition of the healthy fetus allows for safe prolongation of pregnancy. This article reviews the published experience using antepartum fetal biophysical monitoring in patients with PROM.

Biophysical monitoring of melanogenesis as a tool for pigment and hair research.

Biophysical monitoring of melanogenesis as a tool for pigment and hair research.

Spontaneous remission of double pulsatile umbilical venous flow in twin‐twin transfusion syndrome: a case report

Double umbilical pulsatile venous flow is a rare event generally associated with fetal right heart failure. We observed, at 21 weeks' gestation, this venous flow pattern in a case of twin-twin transfusion syndrome occurring in the recipient twin affected by severe hydrops. In spite of a spontaneous remission of fetal hydrops at 30 weeks, the fetus died suddenly in utero, 2 weeks later. We hypothesized that this unexpected event was related to reversed acute twin-twin transfusion, and concluded that fetal hydrops remission in twin-twin transfusion syndrome must not be considered as a reassuring prognostic index but as an indication of the need for continuing biophysical monitoring.

451 The value of daily modified biophysical profile monitoring in predicting infection in premature rupture of membranes (PROM)

451 The value of daily modified biophysical profile monitoring in predicting infection in premature rupture of membranes (PROM)

Umbilical flow waveforms versus fetal biophysical profile in hypertensive pregnancies

The pulsatility index (PI) of the umbilical arteries was measured in 40 hypertensive pregnancies. Doppler-velocimetric data were kept unknown to the clinical staff. An abnormal PI was found in 79% of cases in which an abnormal fetal growth in utero had been diagnosed by ultrasonographic measurements. Serial PI findings showed worsening figures in most of the cases with an abnormal fetal growth, irrespective of the last absolute value. Amniotic fluid estimation and PI data were significantly correlated. PI values were markedly abnormal in fetuses with non-reactive heart-rate tracings. A high sensitivity and an optimal specificity were found for umbilical PI versus the diagnosis of fetal growth retardation made by the coexistence of different biophysical criteria. However, false normal results may occur. 62% of the newborns weighed below the 5th percentile. The sensitivity of abnormal PI values to detect these light fetuses resulted to be only 67%. However the prevalence of neonatal morbidity in fetuses with abnormal PI values was 74%, while morbidity occurred only in 14% of cases with normal PI values. In hypertensive pregnancies, this simple velocimetric parameter proved to correlate with abnormal biophysical monitoring and complicated neonatal outcomes.

The use and misuse of the fetal biophysical profile

The value of the fetal biophysical profile in determining fetal well-being has been well documented. The increasing clinical use of the fetal biophysical profile, however, has led to the recognition of frequent errors in the interpretation and application of this modality. These errors may result in unnecessary interventions or adverse perinatal outcome. The most frequent errors in the interpretation and application of the fetal biophysical profile are described; in an attempt to minimize the misuse of the fetal biophysical profile, an alternative protocol of antepartum fetal evaluation is suggested based upon the information obtained from the biophysical monitoring of the fetus.

Assessment of fetal condition and risk: analysis of single and combined biophysical variable monitoring.

T HE DEVELOPMENT and perfection of specific and accurate diagnostic tests for identification of the fetus at risk for death or damage in utero has long been a major challenge and elusive goal for obstetricians and perinatologists. In recent years, several coaxial and cogent developments within the obstetric community and the community at large have added further impetus to research in methods of fetal risk assessment. In general, the practice of obstetrics, and fetal medicine in particular, has shifted away from reliance on nonspecific maternal clinical marker of potential fetal disease such as fundal height measurements and subjective (perceived) measurement of fetal activity, toward more specific and direct examination of the fetus per se. The advent of diagnostic ultrasound and its evolution from single line display through composite B mode display and recently, to high resolution realtime B mode display, and the concomitant development of Doppler ultrasound from initial instruments, which detected only gross movement, to now highly specialized instruments, which can produce continuous instantaneous heart rate recordings and be used to measure blood flow and velocity in selected fetal and maternal vessels, create a technologic base upon which the knowledge of fetal medicine may be expanded. Medical and surgical advances in the care of maternal diseases in pregnancy. such as hypertension and diabetes, have led to a greater understanding of the influence of these and other disease processes on the developing fetus, in turn creating the need for better discrimination of the fetus at risk. The great advances in neonatal care in recent years have and continue to lower the minima! gestational age at which the transition from fetal to neonatal life may be associated with intact survival. The