scholarly journals Biases in CloudSat Falling Snow Estimates Resulting from Daylight-Only Operations

2021 ◽  
Vol 13 (11) ◽  
pp. 2041
Author(s):  
Lisa Milani ◽  
Norman B. Wood

Falling snow is a key component of the Earth’s water cycle, and space-based observations provide the best current capability to evaluate it globally. The Cloud Profiling Radar (CPR) on board CloudSat is sensitive to snowfall, and other satellite missions and climatological models have used snowfall properties measured by it for evaluating and comparing against their snowfall products. Since a battery anomaly in 2011, the CPR has operated in a Daylight-Only Operations (DO-Op) mode, in which it makes measurements primarily during only the daylit portion of its orbit. This work provides estimates of biases inherent in global snowfall amounts derived from CPR measurements due to this shift to DO-Op mode. We use CloudSat’s snowfall measurements during its Full Operations (Full-Op) period prior to the battery anomaly to evaluate the impact of the DO-Op mode sampling. For multi-year global mean values, the snowfall fraction during DO-Op changes by −10.16% and the mean snowfall rate changes by −8.21% compared with Full-Op. These changes are driven by the changes in sampling in DO-Op and are very little influenced by changes in meteorology between the Full-Op and DO-Op periods. The results highlight the need to sample consistently with the CloudSat observations or to adjust snowfall estimates derived from CloudSat when using DO-Op data to evaluate other precipitation products.

Author(s):  
Anandita Srivastava ◽  
Nalini Kataria

Background: The present investigation was envisaged to find out the impact of extreme hot environmental temperature period (ETP) on marker enzymes of carbohydrate metabolism in male and female non-descript sheep of various age groups i.e. 4 to 13 months from arid tracts of Rajasthan. Glucose-6-phosphate dehydrogenase (G-6-PDH) and malate dehydrogenase (MDH) marker enzymes of carbohydrate metabolism were considered for study. Methods: During the period October 2016-June 2017 blood samples were collected to harvest sera for spectrophotometric method from 240 healthy animals selected from private slaughter house during moderate and extreme hot environmental temperature periods (ETPs). The mean values of markers attained during moderate ETP were reckoned as the control. It was 10.00 ± 0.10 UL-1 and 42.00±1.00 respectively. Conclusion: The mean value of MDH was significantly (p≤0.05) higher while G-6-PDH significantly (p≤0.05) lowers during extreme hot temperature in comparison to moderate period. Therefore, it could be concluded that variations in enzyme markers were associated with changes in environmental temperatures. Probably ETP were able to produce a profound effect on carbohydrate metabolism in sheep. Therfore it can be suggested that during the period of extreme temperature balanced ration must be provided to the animal along with proper management to decrease the severity of temperature impact.


2011 ◽  
Vol 31 (1) ◽  
pp. 01-09 ◽  
Author(s):  
Cláudio E. F. Cruz ◽  
Djeison L. Raymundo ◽  
Cristine Cerva ◽  
Saulo P. Pavarini ◽  
André G. C. Dalto ◽  
...  

Over the last decades, the emphasis on the health of dairy cows has changed from an individual to a herd level. In this scenario, the role played by the recording system and its interpretation by veterinarians has gained primordial importance. The records of productive and reproductive performance and of sanitary status from a southern Brazilian dairy cattle herd have been presented and discussed. The period of study was 2000-2009. Mean values per lactation period were 349D 8436M 290F 275P 201SCS (D: days in lactation, M: kg of milk yield, F: kg of fat, P: kg of protein and SCS: somatic cell score in 1000 cells/ml of milk). Major indexes of reproductive efficiency included age at first calving (31 months), services per conception (2.1), intercalving interval (428 days), calving to conception interval (146 days), mean annual rates of parturitions (76.2%), fetal losses (9.8-19.0%), and stillbirths (3.6%), apart of voluntary waiting period (94 days). Main information on sanitary status of the herd was associated with the mean prevalence of common disorders of dairy cattle such as anaplasmosis (29.8%), mastitis (27.8%), digital diseases (26.3%), ovarian cysts (21.3%), placental retention (19.7%), postpartum uterine infections (10.6%), and calf diarrhea (23.7%) and pneumonia (16.8%), among others. In addition, culling reasons (low reproductive performance [56.3%] and udder/mastitis problems [33.6%]), causes of cattle deaths (anaplasmosis [16.4%] and leukosis [11.4]), and the impact of cattle diseases such as tuberculosis, leukosis, and neosporosis on the herd have also been presented and succinctly discussed. Numbers between brackets represent rates accumulated in the 10-year period.


Author(s):  
Patricia M. Lutz ◽  
Matthias J. Feucht ◽  
Judith Wechselberger ◽  
Michael Rasper ◽  
Wolf Petersen ◽  
...  

Abstract Purpose Ultrasound (US) examination of the medial joint space of the knee has played a subordinate diagnostic role up till now. The purpose of the present study was to describe mean values of medial joint width and to investigate the impact of gender, age, and body mass index (BMI) on medial joint laxity in healthy knees using modern, dynamic US in a standardized fashion in unloaded and standardized loaded conditions. Methods A total of 65 subjects with 79 healthy knees were enrolled in this study. All volunteers underwent clinical examination of the knee. The medial knee joint width was determined using US in a supine position at 0° and 30° of knee flexion in unloaded and standardized loaded (= 15 Dekanewton, daN) conditions using a specific device. Mean values were described and correlations between medial knee joint width and gender, age, and BMI were assessed. Results Thirty-two females and 33 males were enrolled in this study. The mean medial joint width in 0° unloaded was 5.7 ± 1.2 mm and 7.4 ± 1.4 mm loaded. In 30° of knee flexion, the mean medial joint width was 6.1 ± 1.1 mm unloaded and 7.8 ± 1.2 mm loaded. The average change between unloaded and loaded conditions in 0° was 1.7 ± 1.0 mm and in 30° 1.7 ± 0.9 mm. A significant difference between genders was evident for medial joint width in 0° and 30° of flexion in unloaded and loaded conditions (p < 0.05). With rising age, a significant increased change of medial joint space width between unloaded and loaded conditions could be demonstrated in 0° (p = 0.032). No significant correlation between BMI and medial joint width in US could be found. Conclusion Mean values of medial joint width in unloaded and standardized loaded conditions using a fixation device could be demonstrated. Based on the results of this study, medial knee joint width in US is gender- and age-related in healthy knees. These present data may be useful for evaluating patients with acute or chronic pathologies to the medial side of the knee. Level of evidence III.


Author(s):  
Claudia Campana ◽  
Francesco Cocchiara ◽  
Giuliana Corica ◽  
Federica Nista ◽  
Marica Arvigo ◽  
...  

Abstract Context Discordant growth hormone (GH) and insulin-like growth factor-1 (IGF-1) values are frequent in acromegaly. Objective To evaluate the impact of different GH cutoffs on discordance rate. To investigate whether the mean of consecutive GH measurements impacts discordance rate when matched to the last available IGF-1 value. Design Retrospective study. Setting Referral center for pituitary diseases. Patients Ninety acromegaly patients with at least 3 consecutive evaluations for GH and IGF-1 using the same assay in the same laboratory (median follow-up 13 years). Interventions Multimodal treatment of acromegaly. Main Outcome Measures Single fasting GH (GHf) and IGF-1 (IGF-1f). Mean of 3 GH measurements (GHm), collected during consecutive routine patients’ evaluations. Results At last evaluation GHf values were 1.99 ± 2.79 µg/L and age-adjusted IGF-1f was 0.86 ± 0.44 × upper limit of normality (mean ± SD). The discordance rate using GHf was 52.2% (cutoff 1 µg/L) and 35.6% (cutoff 2.5 µg/L) (P = 0.025). “High GH” discordance was more common for GHf &lt;1.0 µg/L, while “high IGF-1” was predominant for GHf &lt;2.5 µg/L (P &lt; 0.0001). Using GHm mitigated the impact of GH cutoffs on discordance (GHm &lt;1.0 µg/L: 43.3%; GHm &lt;2.5 µg/L: 38.9%; P = 0.265). At receiver-operator characteristic curve (ROC) analysis, both GHf and GHm were poor predictors of IGF-1f normalization (area under the curve [AUC] = 0.611 and AUC = 0.645, respectively). The prevalence of disease-related comorbidities did not significantly differ between controlled, discordant, and active disease patients. Discussion GH/IGF-1 discordance strongly depends on GH cutoffs. The use of GHm lessen the impact of GH cutoffs. Measurement of fasting GH levels (both GHf and GHm) is a poor predictor of IGF-1f normalization in our cohort.


Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3283
Author(s):  
Mustafa Demircioglu ◽  
Herwig Bruneel ◽  
Sabine Wittevrongel

Queueing models with disasters can be used to evaluate the impact of a breakdown or a system reset in a service facility. In this paper, we consider a discrete-time single-server queueing system with general independent arrivals and general independent service times and we study the effect of the occurrence of disasters on the queueing behavior. Disasters occur independently from time slot to time slot according to a Bernoulli process and result in the simultaneous removal of all customers from the queueing system. General probability distributions are allowed for both the number of customer arrivals during a slot and the length of the service time of a customer (expressed in slots). Using a two-dimensional Markovian state description of the system, we obtain expressions for the probability, generating functions, the mean values, variances and tail probabilities of both the system content and the sojourn time of an arbitrary customer under a first-come-first-served policy. The customer loss probability due to a disaster occurrence is derived as well. Some numerical illustrations are given.


2020 ◽  
Author(s):  
Zhong-Yi Lin ◽  
Chen-Yen Hsu

&lt;p&gt;(596) Scheila was observed to have an active appearance as a result of impact event in late 2010. In additional the coma feature, the shape of light curve had been found the difference probably fresh material or surface properties changed around the impact site. In this study, we present the results of our monitoring observations obtained in 2014 and 2019-2020. The mean values of the color indices (B&amp;#8722;V&amp;#160;= (0.75 &amp;#177; 0.08)&lt;sup&gt;m&lt;/sup&gt;,&amp;#160;V&amp;#8722;R&amp;#160;= (0.45 &amp;#177; 0.04)&lt;sup&gt;m&lt;/sup&gt;, and&amp;#160;R&amp;#8722;I&amp;#160;= (0.44 &amp;#177; 0.09)&lt;sup&gt;m&lt;/sup&gt;) agree well with the values for asteroids of the D-types. The rotation period of the asteroid estimated from photometric observations in 2014 is 15.8 &amp;#177; 0.1 h.&amp;#160;The shape of the light curve is similar as that found after impact event. Furthermore, we did not find any rotational color variability in B-V, V-R and R-I diagrams, meaning the observed surface in this observing period of 2019-2020 is homogeneous.&lt;/p&gt;


Solid Earth ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 293-305 ◽  
Author(s):  
Sergei Rudenko ◽  
Saskia Esselborn ◽  
Tilo Schöne ◽  
Denise Dettmering

Abstract. A terrestrial reference frame (TRF) is a basis for precise orbit determination of Earth-orbiting satellites, since it defines positions and velocities of stations, the tracking data of which are used to derive satellite positions. In this paper, we investigate the impact of the International Terrestrial Reference Frame realization ITRF2014, as compared to its predecessor ITRF2008, on the quality of orbits, namely, on root-mean-square (rms) fits of observations and orbital arc overlaps of three altimetry satellites (TOPEX/Poseidon, Jason-1, and Jason-2) in the time interval from August 1992 to April 2015 and on altimetry products computed using these orbits, such as single-satellite altimeter crossover differences, radial and geographically correlated mean sea surface height (SSH) errors and regional and global mean sea level trends. The satellite orbits are computed using satellite laser ranging (SLR) and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) observations of a global network of stations. We have found that using ITRF2014 generally improves the orbit quality as compared to using ITRF2008. Thus, the mean values of the rms fits of SLR observations decreased (improved) by 2.4 % and 8.8 % for Jason-1 and Jason-2, respectively, but are almost not impacted for TOPEX/Poseidon when using ITRF2014 instead of ITRF2008. The internal orbit consistency in the radial direction (as derived from arc overlaps) is reduced (improved) by 6.6 %, 2.3 %, and 5.9 % for TOPEX/Poseidon, Jason-1, and Jason-2, respectively. Single-satellite altimetry crossover analyses indicate reduction (improvement) in the absolute mean crossover differences by 0.2 mm (8.1 %) for TOPEX, 0.4 mm (17.7 %) for Jason-1, and 0.6 mm (30.9 %) for Jason-2 with ITRF2014 instead of ITRF2008. The major improvement of the mean values of the rms of crossover differences (0.13 mm; 0.3 %) has been found for Jason-2. Multi-mission crossover analysis shows slight improvements in the standard deviations of radial errors: 0.1 %, 0.2 %, and 1.6 % for TOPEX, Jason-1, and Jason-2, respectively. The standard deviations of geographically correlated mean SSH errors improved by 1.1 % for Jason-1 and 5.4 % for Jason-2 and degraded by 1.3 % for TOPEX. The change from ITRF2008 to ITRF2014 orbits only has minor effects on the estimation of regional and global sea level trends over the 22-year time series from 1993 to 2015. However, on interannual timescales (3–8 years) large-scale coherent trend patterns are observed that seem to be connected to drifts between the origins of the tracking station networks. This leads to the changes in interannual global mean sea level of up to 0.06 mm yr−1 for TOPEX, 0.05 mm yr−1 for Jason-1, and up to 0.12 mm yr−1 for Jason-2, i.e., up to 4 % of the corresponding sea level signal based on altimetry for timescales of 3 to 8 years. The respective changes in the regional sea level trend on these timescales are up to 0.4 mm yr−1 in the time span from April 1993 to July 2008 and up to 1.0 mm yr−1 in the time span from July 2008 to April 2015.


Author(s):  
Feizollah Shahbazi ◽  
Mohamad Analooei ◽  
Ali Saffar

The objective of this experiment was evaluate of the impact damage to pinto bean seeds where seed moisture content (9.25, 12.51, 15.01, 17.52, 20.01% wet basis), impact velocity (5.5, 8, 10, 12.5 and 15m/s) and seed orientation (end and side) were independent variables. The study was conducted under laboratory conditions, using an impact damage assessment device. The results showed that impact velocity, moisture content and seed orientation significantly influenced the physical damages of pinto beans at 1% level. Increasing the impact velocity from 5.5 to 15m/s caused an increase in the mean values of damage from 0.39 to 37.30%. With increase the moisture content from 9.25 to 17.52%, the mean values of percentage of damaged beans decreased significantly from 41.24 to 4.27%. However, by a higher increase in the moisture from 17.52 to 20.01%, the mean values of physically damaged beans showed a nonsignificant increasing trend. There was an optimum moisture level of 17.52% at which seed damage was minimized. The relationship between the percent of physical damage with impact velocity and beans moisture content was expressed mathematically. It was found that the percentage damage to seeds was a quadratic function of moisture content and impact velocity. Impact to the end of the seeds (18.62%) produced the higher damage than side orientation (13.12%).


2017 ◽  
Vol 7 (3) ◽  
pp. 477-484 ◽  
Author(s):  
K. Ghodeif ◽  
R. Wahaab ◽  
S. Sorour

The present work was conducted to document the problems raised regarding low-flow in the Rosetta branch, Egypt and to develop management options to protect drinking water sources. The water quality was monitored during low-flow periods at four drinking water intakes. Results showed an increase in electric conductivity (EC), ammonium (NH4), nitrite (NO2), phosphate (PO4), and total organic carbon (TOC) during the low-flow period. EC ranges from 454 to 1,062 μS/cm and the mean value is 744. Ammonium ranges from 0.38 to 18.5 mg/L and the mean value is 5.45. NO2, PO4, and TOC have mean values of 0.73, 1.85, and 6.71 mg/L, respectively. Statistical evaluation revealed the association of NH4, EC, and PO4 that are good indicators for the load of wastewater. High ammonium often refers to a bad situation regarding oxygen while high nitrite indicates the first oxidation for wastewater through microbiological processes. The low-flow action has a serious impact on drinking water source. A high content of ammonium has delayed coagulation, enhanced algae growth, and prevented the breakpoint being reached during chlorination processes. Potential management options to deal with water scarcity and low-flow, meanwhile reducing the contaminant load in the source drinking water were proposed.


Author(s):  
Isaac Eguarkhide Ogah ◽  
Ekpete A. Ozioma

Introduction: Pollution of the environment by heavy metals has caused serious environmental problems, which threatens the existence of various ecological system, agriculture and human health. This study assessed the comparative analysis of some heavy metals levels in leaves, peels and tubers of cassava planted along East-West Road Rivers State. Materials/Methods: Cassava leaves and tubers samples were collected from farmlands along East-West road (SX, SY and SZ communities, in Emohua, Tai, and Ahoada West LGA respectively), Rivers state, Nigeria. The samples were monitored for heavy metals levels to assess the impact of automobiles on cassava peels, leaves and tubers using Solar Thermo Elementary Atomic Absorption Spectrometer, ModelSG 71906. Metals studied were Lead (Pb), Nickel (Ni), Chromium (Cr), Cadmium (Cd), and Arsenic (As). Results: The mean concentration of Ni present in leaf was 2.81±0.104 mg/kg, tubers recorded 2.23±0.073 mg/kg and peels 3.20±0.06 mg/kg. The highest concentration (4.064±0.035 mg/kg) of Ni was observed in peels while the least concentration (1.80±1.023 mg/kg) was recorded in the tubers. The mean values of Pb in leaves, tubers and peels were 2.22±1.023 mg/kg, 1.80±1.023 mg/kg and 2.64±0.32, highest concentration was recorded in tubers. Arsenic values were 0.16±0.020 mg/kg > 0.51±0.021 mg/kg > 0.38±0.203 mg/kg in peels, tubers and leaves respectively. The values of As were above WHO safe limit of 0.1mg/kg. Also, the mean values of cadmium in leaves, tubers and peels were 0.054±0.570 mg/kg, 0.046±0.057 mg/kg and 0.16±0.609 mg/kg respectively. The highest concentration (0.138±0.109 mg/kg) was in the tubers. Finally, chromium was found to be present in all the cassava samples (leaves, peels and tubers). The mean concentration of chromium (Cr) was 3.58±0.023 mg/kg, 2.76±0.005 mg/kg and 3.83±0.203 mg/kg in leaves, tubers and peels respectively. Conclusion: From the findings, heavy metals were found in the samples and thus, crops should be cultivated far away from major roads.


Sign in / Sign up

Export Citation Format

Share Document