542 research outputs found
Incorporating Rainfall Forecast Data in X-SLIP Platform to Predict the Triggering of Rainfall-Induced Shallow Landslides in Real Time
Extreme and prolonged rainfall resulting from global warming determines a growing need for reliable Landslide Early Warning Systems (LEWS) to manage the risk of rainfall-induced shallow landslides (also called soil slips). Regional LEWS are typically based on data-driven methods because of their greater computational effectiveness, which is greater than the ones of physically based models (PBMs); however, the latter reproduces the physical mechanism of the modelled phenomena, and their modelling is more accurate. The purpose of this research is to investigate the prediction quality of the simplified PBM SLIP (implemented in the X-SLIP platform) when applied on a regional scale by analysing the stability of rain forecasts. X-SLIP was updated to handle the GRIB files (format for weather forecast). Four real-time predictions were simulated on some towns of the Emilia Apennines (northern Italy) involved in widespread soil slips on 5 April 2013; specifically, maps of factors of safety related to this event were derived assuming that X-SLIP had run 72 h, 48 h, 24 h and 12 h in advance. The results indicated that the predictions with forecasts (depending on the forecast quality) are as accurate as the ones derived with rainfall recordings only (benchmark). Moreover, the proposed method provides a reduced number of false alarms when no landslide was reported to occur in the whole area. X-SLIP with rain forecasts can, therefore, represent an important tool to predict the occurrence of future soil slips at a regional scale
Analysis of the Behaviour of Very Slender Piles: Focus on the Ultimate Load
AbstractThe paper aims to analyse the influence of slenderness on the ultimate behaviour of piles with a very small diameter (less than 10 cm) that are often employed in soil reinforcement and for which the slenderness can significatively influence the failure behaviour, reducing the ultimate load. The aim is reached by means of numerical analyses on small-diameter piles of different geometries, embedded in clayey soil. The critical load is evaluated numerically in undrained conditions and then compared to the bearing capacity estimated by the classical approaches based on limit equilibrium method. The numerical model is first calibrated on the basis of the results of experimental laboratory tests on bored piles of a small diameter in a cohesive soft soil (average undrained shear strength cu = 15 kPa). The comparison between the critical load and the bearing capacity shows that their ratio becomes less than 1 for critical slenderness LCR that decreases, nonlinearly, with the decreasing of the pile diameter. The results of the analysis show that varying the diameter of the pile from 0.06 to 0.18 m, LCR varies from 65 to 200. The aforementioned evidence suggests that the evaluation of the ultimate load of piles of very small diameter has to follow the considerations on the critical load of the pile, especially if it is embedded in soft soil; on the contrary for piles of greater diameters (bigger than 20 cm) the buckling is not meaningful because LCR is so big that the common slenderness does not exceed it
Influenza della posizione degli erogatori sulle componenti dello sviluppo e della produzione nell'arancio «Valencia»: risultati preliminari
In this study two irrigation systems (drip and microjet) and different positions of emitters were
compared in a young «Frost Valencia» orange grove.
The following irrigation treatments were set out:
- two drippers (4 l/h each) per tree at apposite distance of 1 m trom the trunk:
- two drippers (4 l/h each) per tree at apposite distance of 0.5 m from the trunk;
- two microjets (65 l/h) per tree at apposite distance of 0.2 m from the trunk.
Both the irrigation systems were able to wet a 3 m strip of soil along the rows, while thc central
part of interrows was kept dry.
Among the wet area drip irrigation induced different soil moisture pattern, since the soil moisture
percentage was greater near the emitters (more than the «field capacity») and particularly at
50 cm depth; and decreased as the distance trom the drippers increased.
The water distribution under the microjets resulted more uniform and the soil moisture reached
the highest values at 25 cm soil depth, alwais close to the emitters.
Leaf water potential and leat diffusive resistance measured at different times did not show any
symptom af water-stress, while trunk growth resulted not affected by different irrigation treatments
Methodology for Determining Dwell Times Consistent with Passenger Flows in the Case of Metro Services
Abstract The importance of a mobility system based on railway technology as the backbone of public transport is now widely acknowledged. Indeed, rail systems are green, high performing, smart and able to ensure a high degree of safety. Therefore, modal split should be steered towards rail transport by increasing the attractiveness of this transport mode. In this context, a key element is represented by the timetabling design phase, which must aim to guarantee an appropriate degree of robustness of rail operations in order to ensure a high degree of system reliability and increase service quality. A crucial factor in the task of timetabling entails evaluating dwell times at stations. The innovative feature of this paper is the analytical definition of dwell times as flow dependent. Our proposal is based on estimating dwell times according to the crowding level at platforms and related interaction between passengers and the rail service in terms of user behaviour when a train arrives. An application in the case of a real metro system is provided in order to show the feasibility of the proposed approach
PTEN as a predictive marker of response to conservative treatment in endometrial hyperplasia and early endometrial cancer. A systematic review and meta-analysis
OBJECTIVE:
Several markers have been studied to predict the responsiveness of endometrial hyperplasia (EH) and early endometrial cancer (EEC) to progestin therapy. PTEN has played a major role in this field, although its predictive significance is still undefined. We aimed to assess if loss of PTEN expression on pre-treatment endometrial specimen may be a predictive markers of response to progestins in EH and EEC.
STUDY DESIGN:
MEDLINE, EMBASE, Web of Sciences, Scopus, ClinicalTrial.gov, OVID and Cochrane Library were searched for relevant articles from the inception to May 2018. All studies assessing PTEN expression as predictive marker in EH and EEC treated with progestin were included. Relative risk (RR) for therapy failure was calculated with 95% confidence interval (CI) and a significant p-value<0.05, with a subgroup analysis based on the histologic category (EEC or EH) and the administration route of progestin (oral or intrauterine).
RESULTS:
Seven cohort studies assessing 376 patients were included. PTEN loss was not significantly associated with the outcome of therapy in the overall analysis (RR = 1.24, 95% CI, 0.88-1.76, p = 0.21), in + the subgroups of EEC (RR = 0.89, 0.32-2.49, p = 0.83), EH (RR = 1.30, 0.90-1.87 p = 0.16), oral progestin (RR = 1.25 0.88-1.79, p = 0.22) and intrauterine device (RR = 1.02, 0.36-2.87, p = 0.97).
CONCLUSION:
PTEN seems not to be useful as predictive marker of response to the conservative treatment of EH and EC, regardless of the administration route (oral or intrauterine) of progestins. We advise future researcher not to further assess PTEN as a stand-alone predictive marker
Fate of a larch unedited tRNA precursor expressed in potato mitochondria.
Abstract In higher plant mitochondria, post-transcriptional C to U conversion known as editing mostly affects mRNAs. However, three tRNAs were also shown to be edited. Among them, three editing sites were identified in larch mitochondrial tRNAHis. We have previously shown that only the edited version can undergo maturation in vitro. In this paper, we introduced via direct DNA uptake the edited or unedited version of larch mitochondrial trnH into isolated potato mitochondria and expressed them under the control of potato mitochondrial 18 S rRNA promoter. As expected, the edited form of larch mitochondrial tRNAHis precursor was processed in the isolated organelles. By contrast, no mature tRNAHis was detected when using the unedited version of trnH. However, precursor molecules could be characterized by reverse transcription-PCR. These data demonstrate that the potato mitochondrial editing machinery is not able to recognize these "foreign" editing sites and confirm that these unedited tRNA precursor molecules are not correctly processed in organello. As a consequence, the fate of these RNA precursor molecules is likely to be degradation. Indeed, we detected by PCR two 3′-end truncated precursor RNAs. Interestingly, both RNA species exhibit poly(A) tails, a hallmark of degradation in plant mitochondria. Taken together, these data suggest that, in plant mitochondria, a defective unedited RNA precursor that cannot be processed to give a mature stable tRNA, is degraded through a polyadenylation-dependent pathway
Hyperhomocysteinemia in women with unexplained sterility or recurrent early pregnancy loss from Southern Italy: a preliminary report
<p>Abstract</p> <p>Background</p> <p>Hyperhomocysteinemia has been described as a risk factor for unexplained recurrent pregnancy loss. Increased levels of homocysteine may be due to inadequate dietary intake of folate and vitamin B12 and inherited defects within the methionine-homocysteine pathway such as MTHFR C677T gene polymorphism. However, the association between hyperhomocysteinemia and sterility problems have been underlined only for recurrent pregnancy loss while a relationship between hyperhomocysteinemia and female sterility is still matter of discussion.</p> <p>Aim</p> <p>This study sought to find out a possible relationship between sterility (primary sterility or secondary sterility due to recurrent pregnancy loss) and homocysteine metabolism.</p> <p>Patients and Methods</p> <p>We selected 20 patients with recurrent pregnancy loss, 20 patients with unexplained female sterility and 20 healthy women as control group. Several whole blood samples were collected by venipuncture. Firstly homocysteinemia and other related variables were tested (i.e. folate and vitamin B12 levels); thereafter DNA was extracted by a further whole blood sample collected in EDTA in order to screen MTHFR C677T gene polymorphism. Statistical analysis was performed by chi square test; differences were considered to be significant if p < 0.05.</p> <p>Results</p> <p>The median fasting total plasma homocysteine concentration was 19.2 ± 6.14 μM for patients with recurrent pregnancy loss, while was 21.05 ± 8.78 μM for patients with unexplained sterility, vs 7.85 ± 3.31 μM of control group (p < 0.05). Fifteen patients with unexplained female sterility showed MTHFR C677T homozigosity vs 17 with recurrent pregnancy loss and 3 in the control group (p < 0.05). On the other hand no significant differences were found in the levels of vitamin B 12 in the three groups, while reduced folate concentrations were found in women with unexplained female sterility and recurrent pregnancy loss (p < 0.05 vs control group.</p> <p>Discussion</p> <p>MTHFR C677T gene polymorphism is frequent in the studied populations. These data raise questions on the role of the homocysteine metabolism in sterility problems. Even though increased homocysteine (i.e. > 15 μM) and MTHFR C677T homozigosity have already been described as risk factors for recurrent pregnancy loss, few studies evaluated their role in women with unexplained sterility. Further studies on larger series are needed to better understand the role of homocysteine metabolism, including folate metabolism, in this clinical setting.</p
Hippotherapy improves gait and balance in Down Syndrome
Patients with Down syndrome (DS) present delays in motor development, showing a unique pattern of locomotion in clinical settings. Hippotherapy (HBR) is a field of rehabilitation therapy to achieve physical, social, and psychological well-being through therapeutic horse riding, providing a new stimulus related to gait and may helping balance and postural control [1], [2]. Herein, we have enrolled fifteen male individuals affected by DS, aged from 19 to 36 years old. All patients were vaccinated for tetanus and previously screened for any contraindications to practice HBR. The HBR protocol included a six-months period of horseback riding exercise, performed weekly. Before, during and after the study period, functional mobility, strength and performance in balance were assessed by Time Up and Go Test (TUG), 30s Chair-Stand-Test (30CST), MRC-scale and the Berg-Balance-Scale (BBS). Furthermore, the OPTO-Gait for dynamic analysis and the Diasu Ultrasensor systems for static analysis were applied at the same timepoints, in order to assess the HBR effects on movement reaction time, muscle activation, functional mobility, muscle strength and balance in DS. In conclusion, we provided objective clinical data on the role of HBR to determine a functional improvement on gait speed, rhythm, width, bilateral symmetry, gross motor function and balance in DS
The role of d-dimer as first marker of thrombophilia in women affected by sterility: implications in pathophysiology and diagnosis of thrombophilia induced sterility
BACKGROUND: D-dimer is considered a marker of hypercoagulable state and of endogenous fibrinolysis, so increased d-dimer is detectable in patients affected by thrombosis. Yet, several studies showed that also infertility, in particular secondary infertility due to recurrent fetal losses, has been often related to thrombotic events, in particular in women carrying thrombotic risk factors such as inherited thrombophilia (MTHFR(C677T), PTHR(A20210G), Factor V Leiden polimorphisms and/or inhAfter this screening we selected 39erited protein C, protein S, AT III deficiency) or acquired thrombophilia (primary antiphospholipid syndrome, acquired protein C, protein S, AT III deficiency, drugs induced thrombophilia). However, because its high predictive negative value in case of suspected thrombosis, increased d-dimer has been often associated to subclinical thrombophilia. The aim of this study is to investigate the role of d-dimer as first marker of thrombophilia in women affected by unexplained infertility and subsequently to search the cause of increased d-dimer, such as inherited and/or acquired thrombophilia. PATIENTS AND METHODS: We selected 79 patients with unexplained primary or secondary infertility. We excluded 40 patients affected by hydrosalpinx, uterine fibroids, uterine malformations, endocrinological and immunological diseases, luteal insufficiency, cytogenetical alterations. All remaining 39 patients were tested for d-dimer and divided in two groups: the patients of group A (25 patients) showed increased plasma d-dimer, in group B were included 14 patients with normal plasma level of d-dimer. After this step all 39 patients were screened for MTHFR(C677T), PTHR(A20210G), Factor V Leiden polimorphisms, protein C, protein S, AT III, anticardiolipin IgM and IgG, lupus anticoagulant. In the control group were included 15 age matched women without sterility problems referred to our outpatient's section of vascular medicine for suspected deep venous thrombosis. Statistical analysis was based on χ(2 )test, differences were considered to be significant if p < 0.05. RESULTS: D-dimer was increased in 25/39 and 20/25 showed inherited/acquired thrombophilia while patients with normal d-dimer showed inherited/acquired thrombophilia in 7/14 (p: < 0.05, s). DISCUSSION: D-dimer is a well known marker of hypercoagulable state, in particular its high predictive negative value in case of suspected thrombosis has been recognised by several reports. Yet, increased d-dimer has been identified also for subclinical thrombophilia besides for vascular thrombosis. Our data, in fact, for the first time suggest an interesting role of d-dimer to identify women affected by unexplained primary or secondary infertility and thrombophilia. So, probably there is a role for d-dimer in these subjects for its predictive positive value. Of course, further data on large based population are needed to confirm our results, because these findings may speed up a diagnostic screening in these patients also for a good cost/effectiveness of this test
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