1,001 research outputs found

    Determination of Evapotranspiration and Crop Coefficient of Cactus Pear (Opuntia ficus-indica Mill.) with an Energy Balance Technique

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    A micrometeorological approach based on surface renewal technique was adopted to estimate evapotranspiration fluxes and crop coefficient data from an irrigated cactus pear (Opuntia ficus-indica Mill.) orchard under Mediterranean climatic conditions. High-frequency temperature readings were taken above the canopy top in order to get surface renewal sensible heat flux values (HSR). These values were compared against eddy covariance sensible heat fluxes (HEC) for calibration. Latent heat flux (or evapotranspiration, ET) was obtained as the residual of the energy balance equation using HSR. In field measurements of biophysical crop features, physiological characteristic and soil hydraulic components were integrated with the analysis of the surface energy fluxes. Microlysimeters were used to compute evaporation rates, allowing the separation of transpiration from ET data. During the irrigation season, evapotranspiration from the cactus pear orchard was 330 mm of water producing 16,210 kg of dry matter ha-1 for a biomass water productivity: WPb = kg biomass m-2 per kg H2O m-2 = 6.6 710-3. The water use efficiency (WUE) was 204 kg H2O kg-1 dry matter. The low value of WPb, relative to other CAM plants, suggests an opportunity to improve the use of irrigation water

    Determination of Evapotranspiration and Annual Biomass Productivity of a Cactus Pear [Opuntia ficus-indica L. (Mill.)] Orchard in a Semiarid Environment

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    A micrometeorological approach based on the surface energy balance was adopted to estimate evapotranspiration fluxes and crop coefficient data from an irrigated cactus pear [Opuntia ficus-indica L. (Mill.)] orchard under Mediterranean climatic conditions. Highfrequency temperature readings were taken above the canopy top to get sensible heat flux values (HSR) using the surface renewal technique. These values were compared against eddy covariance sensible heat fluxes (HEC) for calibration. Latent heat flux (or evapotranspiration, ET) was obtained by solving the daily energy balance equation. Measurements of soil hydraulic components were integrated with the analysis of the surface energy fluxes and crop development in terms of phenology and aboveground biomass accumulation. Microlysimeters were used to compute evaporation rates, allowing the separation of daily transpiration from ET data. Ecophysiological measurements were carried to estimate dry weight accumulation and partitioning. Cactus pear evapotranspired a total of approximately 286 and 252 mm of water during the two monitored growing seasons, respectively. Average daily values of crop (ETc) and reference (ET0) evapotranspiration were in the order of 2.5 and 5.0 mm, respectively, with a corresponding value of the mean crop coefficient of approximately 0.40. The annual dry mass fixed per single tree was 38.8 1.3 kg, with a total production of 12.9 t ha 121, which is comparable to many C3 and C4 plants and resulted in a water use efficiency (WUE) of 4.6 and 4.4 gDMkgH2O 121 in 2009 and 2010, respectively. The stem area index (SAI) was 3.5

    Pluractionality in Hittite: A new look at the suffix -Å¡ke/a-

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    Hittite features three derivational suffixes, i.e., -Å¡ke/a-, -Å¡Å¡a-, and -anna/i-, that attach to verbs and are commonly described as expressing a number of imperfective-like functions. So far, the distribution and use of these suffixes has defied a satisfactory explanation. Whereas some scholars argue that they operate within the domain of lexical aspect, others view them as associated with the encoding of grammatical imperfective aspect. In this paper, we focus on the interpretation of -Å¡ke/a- and argue that a better understanding of the nature of this suffix can be achieved if one frames its description within the typology of pluractional constructions. As we show, the range of polyfunctionality of -Å¡ke/a- fully complies with the cross-linguistic behavior of pluractional markers. We also provide a tentative diachronic scenario that accounts for the rise of such polyfunctionality out of the original semantic core of the suffix

    Retrospective Long-Term Evaluation of Miltefosine-Allopurinol Treatment in Canine Leishmaniosis

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    : Miltefosine-Allopurinol (MIL-AL) combination is reported to be one of the most effective treatments for canine leishmaniosis, thanks to its oral administration and MIL-documented low impact on renal function. However, MIL-AL is considered a second-choice treatment when compared to meglumine-antimoniate-allopurinol combination, mainly due to the risk of earlier relapses. The aim of this study was to evaluate the efficacy of the MIL-AL protocol during a long-term follow-up with an average duration of nine years. Dogs were living in Southern Italy (Puglia, Italy) in an area considered endemic for Canine leishmaniosis (CanL). Inclusion criteria were clinical and/or clinicopathological signs consistent with CanL; positive result to Leishmania quantitative ELISA; and negativity to the most frequent canine vector-borne infections. All dogs received 2 mg/kg MIL for 28 days, and 10 mg/kg AL, BID, for a period varying between 2 and 12 months. Ancillary treatments were allowed according to the clinical condition of the dog. A total clinical score and a total clinicopathological score were calculated at each time point by attributing one point to each sign or alteration present and then by adding all points. Improvement after each treatment was defined by the reduction of at least 50% of the total score. A survival analysis (Kaplan-Meier curve) was performed for quantifying the probability of the events occurring during the study follow-up. The following events were considered: decreased and negative ELISA results; improvement/recovery of the clinical and clinicopathological alterations; and relapse of leishmaniasis. One hundred seventy-three dogs (75f and 98m) were retrospectively included in the study by examining their clinical records since the first diagnosis of CanL. One hundred forty-three (83%) dogs were under five years of age. The mean duration of the follow-up period was 5.4 (±1.1) years with a minimum of 3.2 years and a maximum of 9 years. All dogs received a first treatment of MIL-AL at inclusion; then, during the follow-up course, 30 dogs required a second treatment, 2 dogs required a third treatment and 1 dog required a fourth and a fifth treatment. The mean time interval between the first and the second treatment was 27.2 (±18.3) months. After the first treatment, all dogs had decreased ELISA levels, in an average interval of 2.6 (±1.6) months. One hundred seventy dogs (98%) experienced a clinical improvement (mean time 3.0 ± 4.9 months); 152 (88%) dogs were considered clinically recovered after a mean time of 16.7 ± 13.5 months. A similar trend was observed for clinicopathological alterations; interestingly, proteinuria decreased in most dogs (p < 0.0001-Chi-square for trends). Thirty dogs experienced relapses, the earliest after 4.8 months. The mean time without relapse was 90.4 (±2.5) months. In relapsed dogs, the mean time for clinical improvement after the second treatment was 8.6 (±12.6) months, whereas it was 11.0 (±15.4) months for clinicopathological alterations. Five dogs had limited gastrointestinal side effects associated with MIL treatment. The present study confirms that the MIL-AL protocol can be considered one of the most effective treatments for CanL therapy, mainly for its capacity to provide a long-time clinical improvement in a large majority of treated dogs. As reported in the literature, the clinical stabilization of dogs does not occur immediately after treatment, probably due to the particular pharmacokinetic properties of MIL. The efficacy of MIL-AL decreases in dogs that need more than one treatment, suggesting the necessity to alternate anti-Leishmania drugs for the treatment of relapses. Side effects were transient and slight, even in dogs that required several treatments

    Cerebellum and neurodegenerative diseases: Beyond conventional magnetic resonance imaging

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    The cerebellum plays a key role in movement control and in cognition and cerebellar involvement is described in several neurodegenerative diseases. While conventional magnetic resonance imaging (MRI) is widely used for brain and cerebellar morphologic evaluation, advanced MRI techniques allow the investigation of cerebellar microstructural and functional characteristics. Volumetry, voxel-based morphometry, diffusion MRI based fiber tractography, resting state and task related functional MRI, perfusion, and proton MR spectroscopy are among the most common techniques applied to the study of cerebellum. In the present review, after providing a brief description of each technique's advantages and limitations, we focus on their application to the study of cerebellar injury in major neurodegenerative diseases, such as multiple sclerosis, Parkinson's and Alzheimer's disease and hereditary ataxia. A brief introduction to the pathological substrate of cerebellar involvement is provided for each disease, followed by the review of MRI studies exploring structural and functional cerebellar abnormalities and by a discussion of the clinical relevance of MRI measures of cerebellar damage in terms of both clinical status and cognitive performance

    Clinical translation of [18F]ICMT-11 for measuring chemotherapy-induced caspase 3/7 activation in breast and lung cancer

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    Background: Effective anticancer therapy is thought to involve induction of tumour cell death through apoptosis and/or necrosis. [18F]ICMT-11, an isatin sulfonamide caspase-3/7-specific radiotracer, has been developed for PET imaging and shown to have favourable dosimetry, safety, and biodistribution. We report the translation of [18F]ICMT-11 PET to measure chemotherapy-induced caspase-3/7 activation in breast and lung cancer patients receiving first-line therapy. Results: Breast tumour SUVmax of [18F]ICMT-11 was low at baseline and unchanged following therapy. Measurement of M30/M60 cytokeratin-18 cleavage products showed that therapy was predominantly not apoptosis in nature. While increases in caspase-3 staining on breast histology were seen, post-treatment caspase-3 positivity values were only approximately 1%; this low level of caspase-3 could have limited sensitive detection by [18F]ICMT-11-PET. Fourteen out of 15 breast cancer patients responded to first–line chemotherapy (complete or partial response); one patient had stable disease. Four patients showed increases in regions of high tumour [18F]ICMT-11 intensity on voxel-wise analysis of tumour data (classed as PADS); response was not exclusive to patients with this phenotype. In patients with lung cancer, multi-parametric [18F]ICMT-11 PET and MRI (diffusion-weighted- and dynamic contrast enhanced-MRI) showed that PET changes were concordant with cell death in the absence of significant perfusion changes. Conclusion: This study highlights the potential use of [18F]ICMT-11 PET as a promising candidate for non-invasive imaging of caspase3/7 activation, and the difficulties encountered in assessing early-treatment responses. We summarize that tumour response could occur in the absence of predominant chemotherapy-induced caspase-3/7 activation measured non-invasively across entire tumour lesions in patients with breast and lung cancer

    NUV-HD SiPMs with metal-filled trenches

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    In this paper we present the performance of a new SiPM that is sensitive to blue light and features narrow metal-filled trenches placed in the area around the single-photon avalanche diodes (SPADs) that allow an almost complete suppression the internal optical crosstalk. In particular, we show the benefits of this technological upgrade in terms of electro-optical SiPM performance when compared to the previous technology which had only a partial optical screening between the SPADs. The most relevant effect is the much higher bias voltage that can be applied to the new device before the noise diverges. This allows to optimize and improve both the photon detection efficiency and the single-photon time resolution. We also coupled the SiPMs to LYSO scintillators to verify the performance for possible application in Positron-Emission Tomography. Thanks to the better electro-optical features we were able to measure an improved coincidence time resolution. Furthermore, the optimal voltage operation region is substantially larger, making this SiPM more suitable for real system application where thousands of channels have to provide stable and reproducible performance

    Laminar analysis of the cortical T1/T2-weighted ratio at 7T

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    Objective: In this observational study, we explored cortical structure as function of cortical depth through a laminar analysis of the T1/T2-weighted (T1w/T2w) ratio, which has been related to dendrite density in ex vivo brain tissue specimens of patients with MS. Methods: In 39 patients (22 relapsing-remitting, 13 female, age 41.1 ± 10.6 years; 17 progressive, 11 female, age 54.1 ± 9.9 years) and 21 healthy controls (8 female, , age 41.6 ± 10.6 years), we performed a voxel-wise analysis of T1w/T2w ratio maps from high-resolution 7T images from the subpial surface to the gray matter/white matter boundary. Six layers were sampled to ensure accuracy based on mean cortical thickness and image resolution. Results: At the voxel-wise comparison (p &lt; 0.05, family wise error rate corrected), the whole MS group showed lower T1w/T2w ratio values than controls, both when considering the entire cortex and each individual layer, with peaks occurring in the fusiform, temporo-occipital, and superior and middle frontal cortex. In relapsing-remitting patients, differences in the T1w/T2w ratio were only identified in the subpial layer, with the peak occurring in the fusiform cortex, whereas results obtained in progressive patients mirrored the widespread damage found in the whole group. Conclusions: Laminar analysis of T1w/T2w ratio mapping confirms the presence of cortical damage in MS and shows a variable expression of intracortical damage according to the disease phenotype. Although in the relapsing-remitting stage, only the subpial layer appears susceptible to damage, in progressive patients, widespread cortical abnormalities can be observed, not only, as described before, with regard to myelin/iron concentration but, possibly, to other microstructural features
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