Improving muscle strength and power may mitigate the effects of sarcopenia, but it is unknown if this improves an older adult's ability to recover from a large postural perturbation. Forward tripping ...is prevalent in older adults and lateral falls are important due to risk of hip fracture. We used a forward and a lateral single-step balance recovery task to examine the effects of strength training (ST) or power (PT) training on single-step balance recovery in older adults. Twenty older adults (70.8±4.4 years, eleven male) were randomly assigned to either a 6-week (three times/week) lower extremity ST or PT intervention. Maximum forward (FLean(max)) and lateral (LLean(max)) lean angle and strength and power in knee extension and leg press were assessed at baseline and follow-up. Fifteen participants completed the study (ST =7, PT =8). Least squares means (95% CI) for ΔFLean(max) (ST: +4.1° 0.7, 7.5; PT: +0.6° -2.5, 3.8) and ΔLLean(max) (ST: +2.2° 0.4, 4.1; PT: +2.6° 0.9, 4.4) indicated no differences between groups following training. In exploratory post hoc analyses collapsed by group, ΔFLean(max) was +2.4° (0.1, 4.7) and ΔLLean(max) was +2.4° (1.2, 3.6). These improvements on the balance recovery tasks ranged from ~15%-30%. The results of this preliminary study suggest that resistance training may improve balance recovery performance, and that, in this small sample, PT did not lead to larger improvements in single-step balance recovery compared to ST.
We introduce a microscopic model for the dynamics of the order book to study how the lack of liquidity influences price fluctuations. We use the average density of the stored orders (granularity g) ...as a proxy for liquidity. This leads to a Price Impact Surface which depends on both volume ω and g. The dependence on the volume (averaged over the granularity) of the Price Impact Surface is found to be a concave power law function 〈φ(ω,g)〉
g
∼ω
δ
with δ≈0.59. Instead the dependence on the granularity is φ(ω,g|ω)∼g
α
with α≈-1, showing a divergence of price fluctuations in the limit g→0. Moreover, even in intermediate situations of finite liquidity, this effect can be very large and it is a natural candidate for understanding the origin of large price fluctuations.
A study to determine the incidence of viral diseases in green asparagus (Asparagus officinalis L.) was carried out in Italy, sampling spears, young stems and ferns from commercial fields in several ...regions. Asparagus bunches from supermarkets originating from Italy as well as from several other countries, were also examined. Molecular assays (RT-PCR) were developed for the simultaneous detection of Asparagus virus 1 (AV-1) and Asparagus virus 2 (AV-2). The incidence of the two viruses was quite different. AV-2 was restricted to a few Italian cultivation areas and was never detected in samples from Spain, Peru, Mexico, Ecuador, Argentina, or the USA. In contrast, AV-1 was widely spread in Italian asparagus crops with an average infection rate of about 50.7% and was detected in imported asparagus at different rates. Partial sequences of AV-1 isolates from different geographical areas were obtained. Their 3' terminal genomic region comprising the partial coat protein gene and the 3' untranslated region of 18 isolates were compared to each other and to species of the genus Potyvirus. Results revealed that AV-1 has become the most widespread virus in commercial asparagus crops of Italy, and presumably in other asparagus producing countries. Further, our study provides, for the first time, valuable information on the molecular variability of AV-1 isolates from different parts of the world.
Minimal agent based model for financial markets I Alfi, V.; Cristelli, M.; Pietronero, L. ...
The European physical journal. B, Condensed matter physics,
2/2009, Letnik:
67, Številka:
3
Journal Article
Recenzirano
We introduce a minimal agent based model for financial markets to understand the nature and self-organization of the stylized facts. The model is minimal in the sense that we try to identify the ...essential ingredients to reproduce the most important deviations of price time series from a random walk behavior. We focus on four essential ingredients: fundamentalist agents which tend to stabilize the market; chartist agents which induce destabilization; analysis of price behavior for the two strategies; herding behavior which governs the possibility of changing strategy. Bubbles and crashes correspond to situations dominated by chartists, while fundamentalists provide a long time stability (on average). The stylized facts are shown to correspond to an intermittent behavior which occurs only for a finite value of the number of agents N. Therefore they correspond to finite size effects which, however, can occur at different time scales. We propose a new mechanism for the self-organization of this state which is linked to the existence of a threshold for the agents to be active or not active. The feedback between price fluctuations and number of active agents represents a crucial element for this state of self-organized intermittency. The model can be easily generalized to consider more realistic variants.
Minimal agent based model for financial markets II Alfi, V.; Cristelli, M.; Pietronero, L. ...
The European physical journal. B, Condensed matter physics,
2/2009, Letnik:
67, Številka:
3
Journal Article
Recenzirano
We present a detailed study of the statistical properties of the Agent Based Model introduced in paper I Eur. Phys. J. B, DOI: 10.1140/epjb/e2009-00028-4 and of its generalization to the ...multiplicative dynamics. The aim of the model is to consider the minimal elements for the understanding of the origin of the stylized facts and their self-organization. The key elements are fundamentalist agents, chartist agents, herding dynamics and price behavior. The first two elements correspond to the competition between stability and instability tendencies in the market. The herding behavior governs the possibility of the agents to change strategy and it is a crucial element of this class of models. We consider a linear approximation for the price dynamics which permits a simple interpretation of the model dynamics and, for many properties, it is possible to derive analytical results. The generalized non linear dynamics results to be extremely more sensible to the parameter space and much more difficult to analyze and control. The main results for the nature and self-organization of the stylized facts are, however, very similar in the two cases. The main peculiarity of the non linear dynamics is an enhancement of the fluctuations and a more marked evidence of the stylized facts. We will also discuss some modifications of the model to introduce more realistic elements with respect to the real markets.
Thirty untreated patients, median age 69 years (range 60 - 75 years), with diffuse large B-cell lymphoma (B-DLCL) were treated with a pegylated liposomal doxorubicin (PL-doxorubicin) modified ...CHOP-rituximab regimen. PL-doxorubicin 30 mg m2, was given in combination with standard dosage of prednisone, vincristine, cyclophosphamide, rituximab (according to CHOP-R regimen) every 21 days for six courses. Cardiac toxicity was evaluated by mean of echocardiography for left ventricular ejection fraction (LVEF) evaluations and serum troponin-I levels. Overall response and complete response rates were 76% and 59%. Projected two year event free survival and overall survival are 65.5% and 68.5%. No treatment-related mortality was documented. WHO grade III-IV neutropenia and thrombocytopenia were 86% and 3%. Extra-hematological III-IV toxicity was represented, respectively, by a single case of infection, mucositis, and bleeding. LVEF evaluations and the troponin levels did not show significant changes over the course of the treatment. One patient with a previous history of atrial fibrillation experienced a single episode of arrhythmia. None of the patients developed palmar-plantar erythrodysesthesia.
This regimen appears an active regimen for the treatment of elderly patients with B-DLCL. The replacement of conventional doxorubicin with PL-doxorubicin seems to be associated with a negligible incidence of extra-hematological toxicity, in particular cardiac and infectious complications.
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