Observation Time Research Articles

The effect of care interruptions on mortality in adults resuming antiretroviral therapy.

To estimate the relative rate of all-cause mortality amongst those on antiretroviral treatment (ART) with a history of interruptions compared with those with no previous interruptions in care. Retrospective cohort study. We used data from four South African cohorts participating in the International epidemiology Databases to Evaluate AIDS Southern Africa collaboration. We included adults who started ART between 2004 and 2019. We defined a care interruption as a gap in contact longer than 180 days. Observation time prior to interruption was allocated to a 'no interruption' group. Observation time after interruption was allocated to one of two groups based on whether the first interruption started before 6 months of ART ('early interruption') or later ('late interruption'). We used Cox regression to estimate hazard ratios. Sixty-three thousand six hundred and ninety-two participants contributed 162 916 person-years of observation. There were 3469 deaths. Most participants were female individuals (67.4%) and the median age at ART initiation was 33.3 years (interquartile range: 27.5-40.7). Seventeen thousand and eleven (26.7%) participants experienced care interruptions. Those resuming ART experienced increased mortality compared with those with no interruptions: early interrupters had a hazard ratio of 4.37 (95% confidence interval (CI) 3.87-4.95) and late interrupters had a hazard ratio of 2.74 (95% CI 2.39-3.15). In sensitivity analyses, effect sizes were found to be proportional to the length of time used to define interruptions. Our findings highlight the need to improve retention in care, regardless of treatment duration. Programmes to encourage return to care also need to be strengthened.

Intrinsic doping and ageing of indium oxide thin films

Indium oxide (In2O3) is one of the most used materials for the synthesis of transparent electronics devices and currently tin-doped indium oxide (ITO) dominates the field of Transparent Conductive Oxides for most applications, from ICT to photovoltaics. In this work we present a study on the responses of indium oxide upon the formation, and stabilization, of point defects induced with different methods. After the deposition of In2O3 thin films via RF magnetron sputtering, treatments such as Ion Implantation (I.I.), Ultraviolet (UV) irradiation and Sun exposure were employed to generate oxygen vacancies as intrinsic dopants. Both I.I. and UV irradiations significantly improved the electrical conductivity of films, increasing the carrier density by up to 3 orders of magnitude. Moreover, after I.I. also the crystalline quality of the films was enhanced.To monitor the stability of oxygen vacancies upon exposure to ambient atmosphere, the ageing of samples was followed and recorded for a couple of weeks, reporting a fast and strong degradation of electrical properties. As a facile strategy to counteract the sheet resistance increase, samples were encapsulated in an ultra-thin (≈10 nm) SiO2 layer deposited via sputtering. Irradiated and encapsulated films retained a much lower sheet resistance throughout the observation time, preserving the samples conductivity.

Confrontation between modelled solar integrated observables and direct observations

Context. Stellar variability strongly impacts the search for low-mass exoplanets with radial velocity techniques. Two types of planet-free time series can be used to quantify this impact: models and direct solar observations after a subtraction of the Solar System planetary contribution. Making a comparison among these approaches is necessary to improve the models, which can then be used for blind tests across a broad range of conditions. Aims. Our objective is therefore to validate the amplitude of the convective blueshift in plages used in our previous works, particularly in blind tests, with HARPS-N solar data. Methods. We applied our model to the structures observed at the time of HARPS-N observations and established a direct comparison between the radial velocity time series. To complete our diagnosis, we also studied the observed radial velocities separately for each diffraction order derived from the individual cross-correlation functions, as well as our line-by-line radial velocities. Results. We find that our previous model had been underestimating the amplitude of the convective blueshift inhibition by a factor of about 2. A direct estimation of the convective blueshift in the spectra, which is shown to be correlated with the plage filling factor, allows us to explain the difference with previous estimations obtained with MDI/SOHO Dopplergrams, based on the specific properties of the Ni line used in this mission. In addition, we identified several instrumental systematics, in particular, the presence of a 2 m s−1 peak-to-peak signal with a period of about 200 days in radial velocity and bisector. This signal could be due to periodic detector warmups, a systematic dependence of the long-term trend on wavelength that is possibly related to the variability of the continuum over time, and/or an offset in radial velocity after the interruption of several months in October 2017. Conclusions. A large amplitude in the convective blueshift inhibition of (360 ms−1, namely twice more than in our previous works) must be used when building synthetic times series for blind tests. The presence of instrumental systematics should also be taken into account when using sophisticated methods based on line properties to mitigate stellar activity when searching for very weak signals.

Assessing the Convective Environment over Irrigated and Nonirrigated Land Use with Land–Atmosphere Coupling Metrics: Results from GRAINEX

Abstract Land-use land-cover change affects weather and climate. This paper quantifies land–atmosphere interactions over irrigated and nonirrigated land uses during the Great Plains Irrigation Experiment (GRAINEX). Three coupling metrics were used to quantify land–atmosphere interactions as they relate to convection. They include the convective triggering potential (CTP), the low-level humidity index (HIlow), and the lifting condensation level (LCL) deficit. These metrics were calculated from the rawinsonde data obtained from the Integrated Sounding Systems (ISSs) for Rogers Farm and York Airport along with soundings launched from the three Doppler on Wheels (DOW) sites. Each metric was categorized by intensive observation period (IOP), cloud cover, and time of day. Results show that with higher CTP, lower HIlow, and lower LCL deficit, conditions were more favorable for convective development over irrigated land use. When metrics were grouped and analyzed by IOP, compared to nonirrigated land use, HIlow was found to be lower for irrigated land use, suggesting favorable conditions for convective development. Furthermore, when metrics were grouped and analyzed by clear and nonclear days, CTP values were higher over irrigated cropland than nonirrigated land use. In addition, compared to nonirrigated land use, the LCL deficit during the peak growing season was lower over irrigated land use, suggesting a favorable condition for convection. It is found that with the transition from the early summer to the mid/peak summer and increased irrigation, the environment became more favorable for convective development over irrigated land use. Finally, it was found that regardless of background atmospheric conditions, irrigated land use provided a favorable environment for convective development.

Establishment of a rapid, cost-effective, and accurate method for assessing insect sperm viability

High-quality sperm cells are crucial to reproductive success for both males and post-mating females in animals. Sperm viability, defined as the proportion of viable sperm cells, is used as a sperm quality index and this method has provided new insights into research on reproductive strategies. However, current staining protocols could potentially underestimate viability due to cell damage caused by cell treatments such as high dye concentration and long time for post-mounting. In this study, we established a method that enables rapid sperm viability assessment, has low sperm cell toxicity, and provides precise results regardless of operator expertise, and cost-effective using sperm cells from an ant, Crematogaster osakensis (Hymenoptera). First, to shorten the time for observation of a sufficient number of sperm cells, the volume per field of view was increased by height elevation between the glass slide and the coverslip, thereby we increased the number of sperm cells in a field of view. Second, to reduce sperm cell toxicity, we optimized the minimum dye concentration and incubation time using acridine orange (AO) and Hoechst in addition to SYBR14 and propidium iodide (PI), which has been used in most previous studies. We determined the optimal protocol to be 1 µg/mL AO and 150 µM PI without incubation. Besides, we automated counting sperm cells with ImageJ software and combined with manual correction for more accurate results. We employed the improved method for sperm samples from mealworm beetles (Tenebrio molitor) and silkmoths (Bombyx mori). This method, established through our study, will advance research on reproductive strategies, including sperm competition and sperm quality maintenance in females.

Maintenance proton pump inhibitor use and risk of colorectal cancer: a Swedish retrospective cohort study

ObjectivesWe aimed to evaluate the risk of colorectal adenocarcinoma (CRA) associated with long-term use of proton pump inhibitors (PPIs) in a large nationwide cohort.DesignRetrospective cohort study.SettingThis research was conducted at...

Observation of meteors from space with the Mini-EUSO detector on board the International Space Station

Context. Observations of meteors in the Earth’s atmosphere offer a unique tool for determining the flux of meteoroids that are too small to be detected by direct telescopic observations. Although these objects are routinely observed from ground-based facilities, such as meteor and fireball networks, space-based instruments come with notable advantages and have the potential to achieve a broad and uniform exposure. Aims. In this paper, we describe the first observations of meteor events with Mini-EUSO, a very wide field-of-view telescope launched in August 2019 from the Baikonur cosmodrome and installed on board the Russian Zvezda module of the International Space Station. Mini-EUSO can map the night-time Earth in the near-UV range (290-130 nm) with a field of view equal to 44° × 44° and a spatial resolution of about 4.7 km at an altitude of 100 km from the ground. The detector saves triggered transient phenomena with a sampling frequency of 2.5 µs and 320 µs, as well as a continuous acquisition at 40.96 ms scale that is suitable for meteor observations. Methods. We designed two dedicated and complementary trigger methods, together with an analysis pipeline able to estimate the main physical parameters of the observed population of meteors, such as the duration, horizontal speed, azimuth, and absolute magnitude. To compute the absolute flux of meteors from Mini-EUSO observations, we implemented a simulation framework able to estimate the detection efficiency as a function of the meteor magnitude and the background illumination conditions. Results. The instrument detected 24 thousand meteors within the first 40 data-taking sessions from November 2019 to August 2021, for a total observation time of approximately 6 days with a limiting absolute magnitude of +6. Our estimation of the absolute flux density of meteoroids in the range of mass between 10−5 kg to 10−1 kg was found to be comparable to other results available in the literature. Conclusions. The results of this work prove the potential for space-based observations to increase the statistics of meteor observations achievable with instruments operating on the ground. The slope of the mass distribution of meteoroids sampled with Mini-EUSO suggests a mass index of either s = 2.09 ± 0.02 or s = 2.31 ± 0.03, according to two different methodologies for the computation of the pre-atmospheric mass starting from the luminosity of each event.

Single-Frequency Lasers’ Linewidths Elegantly Characterized with Sigmoid Functions of Observation Time

Single-Frequency Lasers’ Linewidths Elegantly Characterized with Sigmoid Functions of Observation Time

STUDI KOMPARASI UNTUK AS-BUILT SURVEY DAN PENGAWASAN DEFORMASI DARI GEDUNG: METODE TERESTRIS VS METODE SATELIT DI GEDUNG KULIAH UMUM (GKU) INSTITUT TEKNOLOGI SUMATERA

Infrastructure development is one of the main points of the program by the Indonesian government, outlined in Nawacita. One of the manifestations of this program in 2019 was the construction of the Gedung Kuliah Umum (GKU) at the Institut Teknologi Sumatera (Itera). As an effort to realize sustainable development, Geodetic surveys named 'as-built surveys' and periodic deformation observations need to be conducted. Both surveys can be done by terrestrial method using total station and satellite method using GPS-RTK. In this article, an analysis of the accuracy, precision and efficiency of the terrestrial method and satellite method for as-built survey and deformation observation at GKU Itera is reported along with a comparison between deformation calculation and direct observation. It was found that the terrestrial method produced better accuracy and precision level (19,5 cm compared to 43,3 cm) than the satellite method with 95% confidence level. In addition, the terrestrial method produces 3 times more data than the satellite method, although on the other hand, the total observation time of the terrestrial method is 100% longer than the satellite method. These results show that periodic monitoring is important for detecting the degree of deformation and realizing sustainable development. In addition, the terrestrial method is more suitable for accurate and precise periodic surveillance of a building than the satellite method. These findings could act as a contribution towards better sustainable deformation monitiring of a building and to underline the importance of having such periodic observations.

A multimodal aftercare intervention improves the outcome after kidney transplantation – results of the KTx360° aftercare program using claims data

The after-care treatment project KTx360° aimed to reduce graft failure and mortality after kidney transplantation (KTx). The study was conducted in the study centers Hannover, Erlangen and Hannoversch Muenden from May 2017 to October 2020 under the trial registration ISRCTN29416382. The program provided a multimodal aftercare program including specialized case management, telemedicine support, psychological and exercise assessments, and interventions. For the analysis of graft failure, which was defined as death, re-transplantation or start of long-term dialysis, we used longitudinal claims data from participating statutory health insurances (SHI) which enabled us to compare participants with controls. To balance covariate distributions between these nonrandomized groups we used propensity score methodology, in particular the inverse probability of treatment weighting (IPTW) approach. In total, 930 adult participants were recruited at three different transplant centres in Germany, of whom 320 were incident (enrolled within the first year after KTx) and 610 prevalent (enrolled >1 year after KTx) patients. Due to differences in the availability of the claims data, the claims data of 411 participants and 418 controls could be used for the analyses. In the prevalent group we detected a significantly lower risk for graft failure in the study participants compared to the matched controls (HR=0.13, 95% CI=0.04-0.39, p=0.005, n=389 observations), whereas this difference could not be detected in the incident group (HR=0.92, 95% CI=0.54-1.56, p=0.837, n=440 observations). Our findings suggest that a multimodal and multidisciplinary aftercare intervention can significantly improve outcome after KTx, specifically in patients later after KTx. For evaluation of effects on these outcome parameters in patients enrolled within the first year after transplantation longer observation times are necessary. The study was funded by the Global Innovation fund of the Joint Federal Committee of the Federal Republic of Germany, grant number 01NVF16009.

Multiply robust estimation of marginal structural models in observational studies subject to covariate-driven observations.

Electronic health records and other sources of observational data are increasingly used for drawing causal inferences. The estimation of a causal effect using these data not meant for research purposes is subject to confounding and irregularly-spaced covariate-driven observation times affecting the inference. A doubly-weighted estimator accounting for these features has previously been proposed that relies on the correct specification of two nuisance models used for the weights. In this work, we propose a novel consistent multiply robust estimator and demonstrate analytically and in comprehensive simulation studies that it is more flexible and more efficient than the only alternative estimator proposed for the same setting. It is further applied to data from the Add Health study in the United States to estimate the causal effect of therapy counseling on alcohol consumption in American adolescents.

Washed Microbiota Transplantation Is Associated With Improved Lipid Profiles: Long-Term Efficacy and Safety in an Observational Cohort From South China.

Dyslipidemia is one of the main risk factors of chronic metabolic diseases. Our previous studies have shown that washed microbiota transplantation (WMT) has a significant improvement effect on patients with hyperlipidemia and hypolipemia in the Chinese population. The purpose of this study was to further explore the long-term efficacy and safety of WMT in patients with hyperlipidemia. Clinical data of patients who received WMT for multicourse were collected. Changes of blood lipid indexes before and after WMT, including triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), lipoprotein A, and Apolipoprotein B. A total of 124 patients were enrolled, including 56 cases in the hyperlipidemia group and 68 cases with normal lipids. The mean observation time was 787.80 ± 371.45 days, and the longest follow-up time was 1,534 days. TC and non-HDL-C in the hyperlipidemia group with 1-4 courses of WMT were significantly reduced ( P < 0.05); TG decreased significantly after the second course ( P < 0.05); low-density lipoprotein cholesterol also significantly decreased after the fourth course of treatment ( P < 0.05); TG, TC, and non-HDL-C significantly decreased in single course, double course, and multiple course, respectively ( P < 0.05). In terms of time period, over 1 year, the improvement in multicourse treatment was more significant than the single and double-course ones. In terms of comprehensive efficacy, WMT restored 32.14% of patients in the hyperlipidemia group to the normal lipid group ( P < 0.001), of which 30.00% recovered to the normal lipid group within 1 year ( P = 0.004) and 65.38% were reassigned to the normal lipid group over 1 year ( P = 0.003). In addition, over the 1-year treatment period, WMT significantly degraded the high-risk and medium-risk groups of atherosclerotic cardiovascular disease risk stratification in hyperlipidemia cases. There were no serious adverse events. WMT had a long-term improvement effect on patients with hyperlipidemia. The effect of multiple courses over 1 year was more significant than that of single/double courses and also had a significant destratification effect on the risk of atherosclerotic cardiovascular disease with high safety. Therefore, WMT provides a safe and long-term effective clinical treatment for patients with dyslipidemia.

Hot rings on Io observed by Juno/JIRAM

It has been thought that Io’s many paterae may contain lava lakes, but observations by NASA’s Galileo spacecraft at sufficiently high resolution were limited to a few locations, such as Loki Patera. Data acquired by NASA’s Juno mission in May 2023 reveal a common set of thermal characteristics for at least ten paterae on Io, with bright (hot) “thermal rings” around the perimeter of their floors. Loki, Surt, Fuchi, Amaterasu, Mulungu, Chors, and Dazhbog Patera, and four unnamed paterae, all show the same pattern of surface temperature. This new Juno/JIRAM data suggests that hot rings around paterae are a common phenomenon, and that they are indicative of active lava lakes. All the investigated paterae lack recent lava flows on their flanks, suggesting that at the time of observations, the level of the lake was not high enough to overflow the rim. These observations provide insight about the characteristics of paterae’s activity, which may involve either central upwelling of magma, or up-and-down “piston-like” vertical motion of the lake surface. Tidal forces, which are extreme at Io, could play a role as well. Future observations from Juno, particularly during the closest flybys, may indicate which mechanism is more plausible.

Short Communication: A rapid survey of herpetofauna diversity in Bama coastal forest at Baluran National Park, Indonesia

Abstract. Siddiq AM, Wimbaningrum R, Sulistiyowati H, Setiawan R, Setiawan A, Wahono ND. 2024. Short Communication: A rapid survey of herpetofauna diversity in Bama coastal forest at Baluran National Park, Indonesia. Biodiversitas 25: 2323-2329. Scientific reports on herpetofauna in Baluran National Park (BNP) are still limited. Meanwhile, several geographical areas, such as the Bama Baluran National Park coastal forest, have potential herpetofauna diversity within this conservation area yet to be reported. Therefore, this study aimed to determine the diversity of herpetofauna species in BNP's Bama coastal forest (BCF). The method was conducted using the Visual Encounter Survey (VES) in three tracks, conducted by combining Time Restricted Search (TRS) or using observation time for five hours during the mid-afternoon (06.00 AM-11.00 AM) and four hours at night (07.00 PM-11.00 PM) on each track. This study recorded 17 herpetofauna species, comprising 6 amphibian and 11 reptile species, in the BCF of Baluran National Park. The diversity index of herpetofauna species in this area was moderate category (H’=2.25). Species Fejervarya limnocharis Gravenhorst 1829 (38 individuals) has the highest abundance in the BCF and was found in track 1 (swamp area). Meanwhile, three species have the lowest abundance, such as Kaloula baleata Müller 1836, Microhyla palmipes Boulenger 1897, and Cryptoblepharus balinensis Barbour 1911, with 1 individual in each species.

Endodontic Surgery and Post-Treatment Apical Periodontitis: A Systematic Review

Background It has been demonstrated that using innovative root-end filling materials speeds up the success of Endodontic Microsurgery (EMS) on teeth having root filling but still suffering from posttreatment Apical Periodontitis (AP). However, this has reopened the discussion about the long-term effectiveness of EMS conducted on such teeth. Objectives This study aimsto assess the long-term clinical and radiographic outcomes of endodontic surgical procedures in molars with radiographic evidence of secondary AP. Methodology A literature review was undertaken utilizing different databases, including MEDLINE (through PubMed), EMBASE, and Web of Science. The terms used for the search were ‘endodontic microsurgery,’ ‘apical microsurgery,’ ‘periapical disorders,’ ‘root canal therapy,’ ‘apicoectomy,’ ‘retreatment,’ ‘treatment result,’ “retrograde obturation,” and ‘success rate.’ In order to choose the most reliable longitudinal data, specific inclusion and exclusion criteria were established in advance. Only studies that met inclusion criteria for clinical and radiographic outcomes were considered, including prospective clinical studies and randomized clinical trials with at least two-year follow-ups. Results The study of the databases yielded 561 articles in total. From the 115 articles with full texts available, unrelated articles (105) were removed. Our inclusion criteria were met by an overall of ten studies (six prospective clinical studies and four randomized clinical trials). With intervals for follow-up ranging from two to thirteen years, a pooled success rate of 91% from all 451 treated teeth included in the randomized clinical trials and a pooled success rate of 79% from a total of 839 encompassed teeth in the prospective clinical studies were observed. During the same length of time of observation, survival rates ranged from 78% to 100%. Smoking status, tooth position and type, the presence or absence of dentinal abnormalities, the thickness of the bone between the teeth (interproximal bone), and the substance used to fill the space at the end of the roots are the five predictive variables revealed. Conclusion When EMS is performed by skilled endodontists who can deliver high success rates and reliable results, teeth afflicted by secondary AP have a good prognosis and can be preserved.

Microlensing signatures of extended dark objects using machine learning

This paper presents a machine learning-based method for the detection of the unique gravitational microlensing signatures of extended dark objects, such as boson stars, axion miniclusters and subhalos. We adapt MicroLIA, a machine learning-based package tailored to handle the challenges posed by low-cadence data in microlensing surveys. Using realistic observational time stamps, our models are trained on simulated light curves to distinguish between microlensing by pointlike and extended lenses, as well as from other object classes which give a variable magnitude. We focus on boson stars and Navarro-Frenk-White (NFW) subhalos and show that the former, which are examples of objects with a relatively flat mass distribution, can be confidently identified for 0.8≲r/rE≲3. Intriguingly, we also find that more sharply peaked structures, such as NFW subhalos, can be distinctly recognized from point lenses under regular observation cadence. Our findings significantly advance the potential of microlensing data in uncovering the elusive nature of extended dark objects. The code and dataset used are also provided. Published by the American Physical Society 2024

Healing of diabetic ulcers using jamaican cherry leaf extract cream (Muntingia calabura l.) based on collagen density in white rats (Rattus norvegicus)

Abstract This research aims to determine the potential of jamaican cherry leaf extract cream (JCLEC) to accelerate the healing process of diabetic ulcers in white rat based on collagen density. The research used 4 month old male white rats (Rattus norvegicus) which were divided into K0 (negative control), KP (silver sulfadiazine), K1 (5% JCLEC), K2 (10% JCLEC), and K3 (15% JCLEC). An incision was made on the back of the rat then given JCLEC. Days 3, 7, and 14 after treatment, the wound tissue was collected after the rat were euthanized. Skin tissue was processed and stained with picrosirious red. The rate of wound healing was observed. Collagen density was presented in scoring. Based on the treatment group and observation time, there was a significant difference in collagen density between the treatment groups compared to the control (P&lt;0.05). Based on the treatment group, the scoring of the collagen density was 1.78±0.6 (K0); 2.56±0.88 (KP); 1.78±0.4 (K1); 2.56±0.88 (K2); and 3.1±0.78 (K3). Based on observation time, the average collagen density scoring was 1.8±0.3 (D-3); 2.6±0.4 (D-7); and 2.8±0.6 (D-14). The conclusion is the 15% JCLEC has the potential to accelerate the healing of diabetic ulcers in white rats by stimulate collagen density.

Profile red blood cell of local cat during auto skin graft healing which are given platelet rich plasma (PRP) and treated with tilapia fish bio dressing

Abstract The use of auto skin grafts is a solution to rehabilitate the anatomy and function of the wound area. This study aims to observe differences in the red blood profile of local cats using platelet-rich plasma (PRP) and Tilapia Mozambique skin bio-dressing during ASG healing. The study used 6 male domestic cats aged 1-2 years with a body weight of 2-4 kg which were divided into 2 treatment groups. The first surgical procedure, a 2x2 cm wound was created period of 4 days. The second surgical operation involved doing an ASG using a donor from the thoracic region to the area where the wound developed. In the first group (T-I) used bio-dressing, while treatment in the second group (T-II) used bio-dressing added PRP. Blood collection was carried out through the Cephalica antebrachii vein on days 0, 3, 6, 9 and 12 after surgery. The red blood profile including erythrocytes, hemoglobin, hematocrit, mean corpuscular volume (MCV) fluctuated not significantly (P&gt;0.05) while mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and platelets fluctuated significantly. significantly different (P&lt;0.05) between the treatment groups and the time of observation. As an alternate dressing and treatment that can aid in the healing of ASG, PRP and bio dressing can be applied.

Analysis Of Land Subsidance Rates In DKI JAKARTA In 2018, 2020 And 2022 With The DINSAR Method

Abstract DKI Jakarta, the capital city of Indonesia, as the center of growth and development has a high population. The high population has an impact on land use change in an effort to fulfill housing which directly impacts the increase in building density or Normalized Diffrence Built-up Index (NDBI). The purpose of this research is to analyze the rate of land subsidence in DKI Jakarta and analyze the effect of building density on land subsidence. The impact of high growth rates creates the potential for natural and anthropogenic disasters. This research uses the Differential Inferometry Synthetic Aperarure Radar (DinSAR) method, in observing land subsidence with accuracy reaching cm units. The data used in this research is Sentinel 1A image with observation time in 2018, 2020, and 2023. The results showed that land subsidence in DKI Jakarta was dominated in the North Jakarta area, the highest land subsidence value reached -26.08 cm/year. The fastest land subsidence occurs in densely populated areas prone to flooding. The correlation results show that there is no relationship between the high level of building density and land subsidence.

Operational Angular Track Reconstruction in Space Surveillance Radars through an Adaptive Beamforming Approach

In the last few years, many space surveillance initiatives have started to consider the problem represented by resident space object overpopulation. In particular, the European Space Surveillance and Tracking (EUSST) consortium is in charge of providing services like collision avoidance, fragmentation analysis, and re-entry, which rely on measurements obtained through ground-based sensors. BIRALES is an Italian survey radar belonging to the EUSST framework and is capable of providing measurements including Doppler shift, slant range, and angular profile. In recent years, the Music Approach for Track Estimate and Refinement (MATER) algorithm has been developed to retrieve angular tracks through an adaptive beamforming technique, guaranteeing the generation of more accurate and robust measurements with respect to the previous static beamforming approach. This work presents the design of a new data processing chain to be used by BIRALES to compute the angular track. The signal acquired by the BIRALES receiver array is down-converted and the receiver bandwidth is split into multiple channels, in order to maximize the signal-to-noise ratio of the measurements. Then, the signal passes through a detection block, where an isolation procedure creates, for each epoch, signal correlation matrices (CMs) related to the channels involved in the detection and then processes them to isolate the data stream related to a single detected source. Consequently, for each epoch and for each detected source, just the CM featuring the largest signal contribution is kept, allowing deriving the Doppler shift measurement from the channel illumination sequence. The MATER algorithm is applied to each CM stream, first estimating the signal directions of arrival, then grouping them in the observation time window, and eventually returning the target angular track. Ambiguous estimates may be present due to the configuration of the receiver array, which cause spatial aliasing phenomena. This problem can be addressed by either exploiting transit prediction (in the case of cataloged objects), or by applying tailored criteria (for uncatalogued objects). The performance of the new architecture was assessed in real operational scenarios, demonstrating the enhancement represented by the implementation of the channelization strategy, as well as the angular measurement accuracy returned by MATER, in both nominal and off-nominal scenarios.