1,560 research outputs found
Regulation Support to Industrial Clusters: A Cross-Country Analysis
We empirically investigate the role of regulatory governance and industrial clusters to foster the country\u2019s economic performance. Using the ordinary least-square (OLS) regression for a cross section of countries, including the 25 EU Member States, our findings show that the regulation governance has the strongest effects on the employment rate performing a buffering effect with the cluster development. An antagonist effect occurs for the other economic indicators
Renal Involvement in the Acquired Immunodeficiency Syndrome: Presentation, Clinical Course, and Therapy
Acute renal failure developing during the clinical course of the acquired immunodeficiency syndrome (AIDS) has been related to complications of sepsis, nephrotoxic antibiotics, and recently to the development of glomerular lesions. Of 114 AIDS patients admitted to our hospital between January 1985 and June 1986. II patients (9.6%) developed acute renal failure. None of these II patients had a history of intravenous drug abuse or hypertension. All patients were male with an average age of 35 years old, 81% were black, and all were bisexual or homosexual. Renal failure was attributed to AIDS-related focal glomerulosclerosis (five cases), prerenal azotemia (one case), acute interstitial nephritis (one case), and acute tubular necrosis [four cases). Approximately 15 weeks elapsed from the onset of renal failure to end-stage kidney disease. Only one of five patients survived more than six months after beginning dialysis. Acute renal failure is an important complication of AIDS with glomerular involvement detected in 45% of patients. The long-range problems of initiating and maintaining dialysis therapy in these patients need to be addressed
MicroRNA-222 regulates muscle alternative splicing through Rbm24 during differentiation of skeletal muscle cells
A number of microRNAs have been shown to regulate skeletal muscle development and differentiation. MicroRNA-222 is downregulated during myogenic differentiation and its overexpression leads to alteration of muscle differentiation process and specialized structures. By using RNA-induced silencing complex (RISC) pulldown followed by RNA sequencing, combined with in silico microRNA target prediction, we have identified two new targets of microRNA-222 involved in the regulation of myogenic differentiation, Ahnak and Rbm24. Specifically, the RNA-binding protein Rbm24 is a major regulator of muscle-specific alternative splicing and its downregulation by microRNA-222 results in defective exon inclusion impairing the production of muscle-specific isoforms of Coro6, Fxr1 and NACA transcripts. Reconstitution of normal levels of Rbm24 in cells overexpressing microRNA-222 rescues muscle-specific splicing. In conclusion, we have identified a new function of microRNA-222 leading to alteration of myogenic differentiation at the level of alternative splicing, and we provide evidence that this effect is mediated by Rbm24 protei
Comparison of SWAP and FAO Agro-Hydrological Models to Schedule Irrigation of Wine Grape
This paper compares two agro-hydrological models that are used to schedule irrigation of a typical Mediterranean crop. In particular, a comparison between the Food and Agriculture Organization (FAO) model, which uses a black box approach, and the soil-water-atmosphere-plant (SWAP) model, which is based on the numerical analysis of Richards' equation, are shown for wine grape. The comparison was carried out for the 2005 and 2006 irrigation seasons and focused on hydrological balance components and on soil water contents. Next, the ordinary scheduling parameters were identified so that the performance of the two models, which aimed to evaluate the seasonal water requirements and the irrigation times, could be assessed. In the validation phase, both of the models satisfactorily simulated the soil water content, and comparable values of cumulative evapotranspiration were obtained. With the goal of recognizing the crop water stress condition in the field, the original algorithm of the FAO model was modified. This research provided evidence of how the two agrohydrological models, although characterized by different approaches in modeling the phenomena, showed a similar behaviour when used for scheduling irrigation under soil water deficit conditions. © 2012 American Society of Civil Engineers
Kainic acid-induced seizures modulate Akt (SER473) phosphorylation in the hippocampus of dopamine D2 receptor knockout mice.
Dopamine D2 receptor (D2R) signalling has been shown to modulate seizure-induced hippocampal cell death. D2R knockout (D2R-/-) mice are more susceptible to kainic acid (KA)-induced excitotoxicity, displaying cell death in the CA3 subfield of the hippocampus at KA doses not damaging in wild-type (WT) animals. Absence of D2R signalling in the hippocampus leads to activation (dephosphorylation) of glycogen synthase kinase 3β (GSK-3β) after KA (20 mg/kg), which is not associated with a change in the phosphorylation of the GSK-3β regulator Akt at the canonical threonine 308 residue. In the present study, we investigated alternative pathways responsible for the activation of GSK-3β in the hippocampus of the D2R-/- mice 24 h following KA-induced seizures. Here, we show that phosphorylation of Akt occurs at serine 473 (Ser473) in the CA3 region of WT but not D2R-/- mice following KA. Moreover, the CA1 subregion, which does not undergo neurodegeneration in either WT or D2R-/- mice, displays a strong induction of Akt (Ser473) phosphorylation after KA. Additionally, the vulnerability in the CA3 is not associated with changes to p38MAPK and Dishevelled activation, and β-catenin does not appear to be a downstream target of the GSK-3β. Thus, we propose that GSK-3β phosphorylation-mediated hippocampal cell survival may depend on Akt (Ser473) phosphorylation; loss of D2R-mediated signalling in the CA3 region of D2R-/- mice leads to reduced Akt (Ser473) phosphorylation rendering neurons more vulnerable to apoptosis. Further investigation is required to fully elucidate the GSK-3β targets involved in D2R-dependent response to excitotoxicity
A cross-layer architecture for satellite network security: CL-IPsec
Cross-layer architectures (CLAs) are proposed to improve performance in networks where physical layer impairments are unpredictable and provision of security services may be challenging, as in satellite networks. This paper proposes an extension to the IPsec protocol, named Cross-Layer IPsec (CL-IPsec), able to provide authentication and integrity services through a cross-layer architecture when the adopted protocol is UDP-Lite. This is suitable for multicast applications that are cost-effectively provided by satellite systems. A satellite emulation platform has been used to validate the CL-IPsec implementation and to evaluate the performance improvement derived from the proposed CLA. © 2008 IEEE
Combined use of eddy covariance and sap flow techniques for partition of ET fluxes and water stress assessment in an irrigated olive orchard
Correct estimation of crop actual transpiration plays a key-role in precision irrigation scheduling, since crop growth and yield are associated to the water passing through the crop. Objective of the work was to assess how the combined use of micro-meteorological techniques (eddy covariance, EC) and physiological measurements (sap flow, SF) allows a better comprehension of the processes involving in the Soil-Plant-Atmosphere continuum. To this aim, an experimental dataset of actual evapotranspiration, plant transpiration, and soil water content measurements was collected in an olive orchard during the midseason phenological period of 2009 and 2010. It was demonstrated that the joint use of EC and SF techniques is effective to evaluate the components of actual evapotranspiration in an olive orchard characterized by sparse vegetation and a significant fraction of exposed bare soil. The availability of simultaneous soil water content measurements allowed to estimate the crop coefficients and to assess a simple crop water stress index, depending on actual transpiration that can be evaluated even in the absence of direct measurements of actual transpiration. The crop coefficients experimentally determined resulted very similar to those previously evaluated; in particular, in the absence of water stress, a seasonal average value of about 0.65 was obtained for the "single" crop coefficient, whereas values of a 0.34 and 0.41 were observed under limited water availability in the root zone. The comparison between the values of crop water stress index evaluated during the investigated periods evidenced systematically lower values (less crop water stress) in the first year compared to the second, according to the general trend of soil waters content in the root zone. Further researches are however necessary to extent the experimental dataset to periods characterized by values of soil evaporation higher than those observed, in order to verify the crop coefficients even under different conditions than those investigated. © 2012 Elsevier B.V
Evaluating the performance of reference evapotranspiration equations with scintillometer measurements under Mediterranean climate and effects on olive grove actual evapotranspiration estimated with FAO-56 water balance model
The concept of reference potranspiration is widely used to support water resource management in
agriculture and for irrigation scheduling, especially under arid and semi-arid conditions. The Penman-Monteith
standardized formulations, as suggested by ASCE and FAO-56 papers, are generally applied for accurate
estimations of ETo, at hourly and daily scale. When detailed meteorological information are not available, several
alternative and simplified equations, using a limited number of variables, have been proposed (Blaney-Criddle,
HargreavesSamani, Turc, Makkinen and Pristley-Taylor).
In this paper, scintillometer measurements collected for six month in 2005, on an experimental plot under
“reference” conditions, were used to validate different ETo equations at hourly and daily scale. Experimental plot
is located in a typical agricultural Mediterranean environment (Sicily, Italy), where olive groves is the dominant
crop.
As proved by other researches, the comparison confirmed the best agreement between estimated and measured
fluxes corresponds to FAO-56 Penman-Monteith standardized equation, that was characterized by both the
lowest average error and the minimum bias. However, the analysis also evidenced a quite good performance of
Pristley-Taylor equation, that can be considered as a valid alternative to the more sophisticated PenmanMonteith
method.
The different ETo series, obtained by the considered simplified equations, were then used as input in the FAO-56
water balance model, in order to evaluate, for olive groves, the errors on estimated actual evapotranspiration ET.
To this aim soil and crop model input parameters were settled by considering previous experimental researches
already used to calibrate and validate the FAO-56 water balance model on olive groves, for the same study area.
Also in this case, assuming as the true values of ET those obtained using the water balance coupled with Penman-
Monteith ETo input values, the Priestley-Taylor equation, requiring a limited number of input meteorological
data, was characterized by the best performance if compared to the other equations used to evaluate ETo. Under
environments conditions similar to those considered therefore, according to the good performance associated
to the Priestley-Tailor approach, FAO-56 model can allow realistic estimation of ET, even in absence of a full meteorological dataset
Network layer security: Design for a cross layer architecture
Traditional modular layering schemes have served a major part in the development of a variety of protocols. However, as the physical layer impairments become more unpredictable, a cross layer design (CLD) which is dynamic in nature provides better performance. CLD introduces new challenges in protocol design as well as in the area of security. Using numerical analysis, we show that a link layer design employing header compression and cross layer signalling to protect protocol headers can limit packet discarding. This paper also reviews the IPsec protocol and describes how IPsec can be modified for cross layer architecture. © 2007 IEEE
Assessing agro-hydrological models to schedule irrigation for crops of Mediterranean enviroment
Despite in Mediterranean environment water resources for irrigation are limited, water management
for agriculture is often practiced ignoring principles of environmental sustainability.
Objective of the paper is to asses the possibility of using agro-hydrological models for irrigation scheduling, in
order to optimize the water use efficiency.
The results of a comparison between the numerical SWAP model and the functional model proposed by
FAO to estimate water requirements in two typical arboreal Mediterranean Crops (grapevine and olive) are
showed.
In the initial phase of the research, involving both irrigation seasons 2005 and 2006, after a preliminary
analysis of soil hydraulic and biophysical plant parameters, two intensive field measurements campaigns
were carried out to measure the soil water content at different depths, to proceed to the validation of both the
models.
Validation of the model was carried out by means of the comparison between measured and predicted soil
water content.
Finally different irrigation scheduling options were examined, in order to compare the scheduled irrigation
times with those planned by the farmers.
The results of investigations evidenced that FAO model simulates reliably the values of average water content
of the soil profile, even if a certain overestimation of evapotranspiration fluxes can be observed with the FAO
56 model compared with SWAP. Consequently, the FAO model anticipates the starting date for irrigation
obtained with SWAP, but, in terms of seasonal water requirements, the estimates determined by the two
modes did not result significantly different
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