788 research outputs found
Interseismic strain accumulation along the western boundary of the Indian subcontinent
Despite an overall sinistral slip rate of approximately 3 cm/yr, few major earthquakes have occurred in the past 200 years along the Chaman fault system, the western boundary of the India Plate with the Eurasia Plate. GPS and InSAR data reported here indicate sinistral shear velocities of 8-17 mm/yr across the westernmost branches of the fault system, suggesting that a significant fraction of the plate boundary slip is distributed in the fold and fault belt to the east. At its southernmost on-land segment, near the triple junction between the Arabia, Eurasia, and India Plates, we find the velocity across the Ornach Nal fault is 15.1+13.4+16.9 mm/yr, with a locking depth probably less than 3 km. At latitude 30 degrees N near the town of Chaman, Pakistan, where a M6.5 earthquake occurred in 1892, the velocity is 8.5+6.8 +10.3 mm/yr and the fault is locked at approximately 3.4 km depth. At latitude 33 degrees N and further north, InSAR data indicate a velocity across the Chaman fault of 16.8±2.7 mm/yr. The width of the plate boundary varies from several km in the south where we observe approximately 2 mm/yr of convergence near the westernmost strike-slip faults, to a few hundreds of km in the north where we observe 6–9 mm/yr of convergence, and where the faulting becomes distinctly transpressional. The shallow locking depth along much of the transform system suggests that earthquakes larger than those that have occurred in the historical record would be unexpected, and that the recurrence interval of those earthquakes that have occurred is of the order of one or two centuries, similar in length to the known historical record
Fracture healing following high energy tibial trauma: Ilizarov versus Taylor Spatial Frame
Introduction: The optimal treatment of high energy tibial fractures remains controversial and a challenging orthopaedic problem. The role of external fi xators for all these tibial fractures has been shown to be crucial. Methods: A fi ve-year consecutive series was reviewed retrospectively, identifying two treatment groups: Ilizarov and Taylor Spatial Frame (TSF; Smith & Nephew, Memphis, TN, US). Fracture healing time was the primary outcome measure. Results: A total of 112 patients (85 Ilizarov, 37 TSF) were identifi ed for the review with a mean age of 45 years. This was higher in women (57 years) than in men (41 years). There was no signifi cant difference between frame types (p=0.83). The median healing time was 163 days in both groups. There was no signifi cant difference in healing time between smokers and non-smokers (180 vs 165 days respectively, p=0.07), open or closed fractures (p=0.13) or age and healing time (Spearman's r=0.12, p=0.18). There was no incidence of non-union or re-fracture following frame removal in either group. Conclusions: Despite the assumption of the rigid construct of the TSF, the median time to union was similar to that of the Ilizarov frame and the TSF therefore can play a signifi cant role in complex tibial fractures
The Devastating 2022 M6.2 Afghanistan Earthquake: Challenges, Processes, and Implications
On June 21st, a Mw6.2 earthquake struck the Afghan-Pakistan-border-region, situated within the India-Asia collision. Thousand thirty-nine deaths were reported, making the earthquake the deadliest of 2022. We investigate the event\u27s rupture processes by combining seismological and geodetic observations, aiming to understand what made it that fatal. Our Interferometric Synthetic Aperture Radar-constrained slip-model and regional moment-tensor inversion, confirmed through field observations, reveal a sinistral rupture with maximum slip of 1.8 m at 5 km depth on a N20°E striking, sub-vertical fault. We suggest that not only external factors (event-time, building stock) but fault-specific factors made the event excessively destructive. Surface rupture was favored by the rock foliation, coinciding with the fault strike. The distribution of Peak-Ground-Velocity was governed by the sub-vertical fault. Maximum slip was large compared to other events globally and might have resulted in peak-frequencies coinciding with resonance-frequencies of the local buildings and demonstrates the devastating impact of moderate-size earthquakes
Sex-specific independent risk factors of urinary incontinence in acute stroke patients:a multicentre registry-based cohort study
BackgroundThe presence of urinary incontinence (UI) in acute stroke patients indicates poor outcomes in men and women. However, there is a paucity and inconsistency of data on UI risk factors in this group and hence we conducted a sex-specific analysis to identify risk factors.MethodsData were collected prospectively (2014–2016) from the Sentinel Stroke National Audit Program for patients admitted to four UK hyperacute stroke units. Relevant risk factors for UI were determined by stepwise multivariable logistic regression, presented as odds ratios (OR) and 95% confidence intervals (CI).ResultsThe mean (±SD) age of UI onset in men (73.9 year ± 13.1; n = 1593) was significantly earlier than for women (79.8 year ± 12.9; n = 1591: p < 0.001). Older age between 70 and 79 year in men (OR = 1.61: CI = 1.24–2.10) and women (OR = 1.55: CI = 1.12–2.15), or ≥80 year in men (OR = 2.19: CI = 1.71–2.81), and women (OR = 2.07: CI = 1.57–2.74)–reference: <70 year–both predicted UI. In addition, intracranial hemorrhage (reference: acute ischemic stroke) in men (OR = 1.64: CI = 1.22–2.20) and women (OR = 1.75: CI = 1.30–2.34); and prestroke disability (mRS scores ≥ 4) in men (OR = 1.90: CI = 1.02–3.5) and women (OR = 1.62: CI = 1.05–2.49) (reference: mRS scores < 4); and stroke severity at admission: NIHSS scores = 5–15 in men (OR = 1.50: CI = 1.20–1.88) and women (OR = 1.72: CI = 1.37–2.16), and NIHSS scores = 16–42 in men (OR = 4.68: CI = 3.20–6.85) and women (OR = 3.89: CI = 2.82–5.37) (reference: NIHSS scores = 0–4) were also significant. Factors not selected were: a history of congestive heart failure, hypertension, atrial fibrillation, diabetes and previous stroke.ConclusionsWe have identified similar risk factors for UI after stroke in men and women including age >70 year, intracranial hemorrhage, prestroke disability and stroke severity
Treated residential greywater and its effect on shoot dry matter and nutrient uptake in maize (Zea mays)
This is the final version. Available from the publisher via the DOI in this record.Shortage of freshwater resources and limited fertilizer usage due to cost related issues in agriculture are the basic limiting
factors in food production. This study evaluated the effect of greywater application on shoot dry mater and uptake of maize
crop. The experiment included five treatments canal water, untreated greywater and treated greywater through reed bed
technology using Cyperus iria, Phragmites karka and Typha elephantina, arranged in a randomized complete block design.
All the treatments received a basal doze of NPK fertilizer. The soil used in the experiment was silty clay in texture with 55%
clay, pH - 7.70, EC - 1.07 dS m-1
, CaCO3 - 12.50% organic matter - 0.17%, NO3-N – 4.60 mg kg-1
, NH4-N – 1.68 mg kg-1
,
ammonium bicarbonate diethylene triamine penta acetic acid (AB-DTPA) extractable P and K as 0.18 and 270 mg kg-1
,
respectively. The treated greywater had a highly significant effect on shoot dry matter and N, P and K uptake in maize. The
highest contents were found in treatments applied with greywater, treated under reed bed technology using Cyperus iria and
the lowest in canal water applied treatments. Part of applied fertilizer was supplemented through greywater application
Thermal history modeling of the H chondrite parent body
The cooling histories of individual meteorites can be empirically
reconstructed by using ages from different radioisotopic chronometers with
distinct closure temperatures. For a group of meteorites derived from a single
parent body such data permit the reconstruction of the cooling history and
properties of that body. Particularly suited are H chondrites because precise
radiometric ages over a wide range of closure temperatures are available. A
thermal evolution model for the H chondrite parent body is constructed by using
all H chondrites for which at least three different radiometric ages are
available. Several key parameters determining the thermal evolution of the H
chondrite parent body and the unknown burial depths of the H chondrites are
varied until an optimal fit is obtained. The fit is performed by an 'evolution
algorithm'. Empirical data for eight samples are used for which radiometric
ages are available for at least three different closure temperatures. A set of
parameters for the H chondrite parent body is found that yields excellent
agreement (within error bounds) between the thermal evolution model and
empirical data of six of the examined eight chondrites. The new thermal model
constrains the radius and formation time of the H chondrite parent body
(possibly (6) Hebe), the initial burial depths of the individual H chondrites,
the average surface temperature of the body, the average initial porosity of
the material the body accreted from, and the initial 60Fe content of the H
chondrite parent body.Comment: 16 pages, 7 figure
Diagnostic confusion resolved by being upbeat
The classical stroke presentation – captured by the public health campaign mnemonic FAST (face, arm, speech, time) – does not apply in a large number of stroke cases; yet establishing a prompt diagnosis is imperative for optimal management. Here, we describe a patient with acute bulbar weakness, numbness in all extremities and an apparently normal magnetic resonance imaging (MRI) of the brain upon admission for whom even the fundamental question of whether this reflected a central or peripheral nervous system process was unclear. The critical localizing sign was upbeat nystagmus that denotes a brainstem cause. MRI of the brain in the second week confirmed a diagnosis of medial medullary infarction
PCA-based lung motion model
Organ motion induced by respiration may cause clinically significant
targeting errors and greatly degrade the effectiveness of conformal
radiotherapy. It is therefore crucial to be able to model respiratory motion
accurately. A recently proposed lung motion model based on principal component
analysis (PCA) has been shown to be promising on a few patients. However, there
is still a need to understand the underlying reason why it works. In this
paper, we present a much deeper and detailed analysis of the PCA-based lung
motion model. We provide the theoretical justification of the effectiveness of
PCA in modeling lung motion. We also prove that under certain conditions, the
PCA motion model is equivalent to 5D motion model, which is based on physiology
and anatomy of the lung. The modeling power of PCA model was tested on clinical
data and the average 3D error was found to be below 1 mm.Comment: 4 pages, 1 figure. submitted to International Conference on the use
of Computers in Radiation Therapy 201
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